Treatment of amyotrophic lateral sclerosis

ABSTRACT

The present invention relates to the identification of compounds and pharmaceutical compositions thereof for treating subjects with amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases. The invention also provides methods of preparing the provided compounds.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional application Ser. No. 61/116,571, filed Nov. 20, 2008, the entirety of which is hereby incorporated herein by reference.

GOVERNMENT SUPPORT

This application is a United States National Phase Application under 35 U.S.C. § 371 of International PCT Application No. PCT/US09/06237, filed Nov. 20, 2009, which claims priority to U.S. provisional application Ser. No. 61/116,571, filed Nov. 20, 2008, the entirety of each of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder caused by motor neuron death (Rowland et al., N. Engl. J. Med., 2001, 334, 1688-1700) and characterized in part by the presence of abnormal aggregates of insoluble protein in selectively vulnerable populations of neurons and glia. ALS, an orphan disease, is estimated to afflict about 87,000 people worldwide, but its prevalence would be much higher were it not for the fact that ALS patients survive for only 3 to 5 years on average after diagnosis. Approximately 10% of ALS cases are familial, with the rest of the cases being sporadic (Rowland et al., N. Engl. J. Med., 2001, 334, 1688-1700). Approximately 20% of the cases of familial ALS are caused by inherited mutations in the protein Cu/Zn superoxide dismutase (SOD1) (Rosen et al., Nature, 1993, 362, 59-62). Rodent models in mutant SOD1 are often used as a disease model because of its phenotypic and pathologic resemblance to sporadic and familial human ALS (Dal Canto et al., Brain Res., 1995, 676, 25-40; Wong, et al., Neuron, 1995, 14, 1105-1116; Bruijin et al., Science, 1998, 281, 1851-1854; Bruijn et al., Neuron, 1997, 18, 327-338; Wang et al., Hum. Mol. Genet., 2003, 12, 2753-2764; Wang et al., Neurobiol. Dis., 2002, 10, 128-138; Jonsson et al., Brain, 2004, 127, 73-88).

The causes of sporadic ALS remain unknown, and the clinical courses are variable, suggesting that multiple factors are involved. Different hypotheses have been proposed, such as glutamate-mediated excitotoxicity, impaired mitochondrial function, oxidative stress, and aberrant protein aggregation (Dib et al., Drugs, 2003, 63, 289-310; Strong et al., Pharmacology & Therapeutics, 2003, 98, 379-414; Kunst et al., Am. J. Hum. Genet., 2004, 75, 933-947; Bruijn et al., Annu. Rev. Neurosci, 2004, 27, 723-749; Dibernardo et al., Biochimica et Biophysica Acta, 2006, 1762, 1139-1149). Riluzole, which decreases glutamate excitotoxicity, is the only FDA approved ALS drug (Jimonet et al., J. Med. Chem., 1999, 42, 2828-2843). However, it can only extend median survival life for 2 to 3 months, suggesting mechanisms other than glutamate-mediated excitotoxicity should be considered during ALS drug development (Miller et al., ALS and Other Motor Neuron Disorders, 2003, 4, 191-206; Taylor et al., Neurology, 2006, 67, 20-27).

Imbalances in protein homeostasis, which can be caused by cell stress or expression of certain mutant proteins, can result in the appearance of alternative conformational states that are able to self-associate to form protein aggregates and inclusion bodies. In familial as well as sporadic forms of ALS and mutant SOD1 transgenic models, aberrant protein aggregation has been reported as a common feature (Bruijin et al., Science, 1998, 281, 1851-1854; Leigh et al., Cytoskeletalpathology in Motor Neuron Diseases, in: Rowland, L. P. (Editor), Amyotrophic Lateral Sclerosis and Other Motor Neuron Disease, Raven Press, New York, 1991, pp. 3-pp. 23; Mather et al., Neurosci. Lett., 1993, 160, 13-16; Pasinelli et al., Neuron, 2004, 43, 19-30; Watanabe, et al., Neruobiol. Dis., 2001, 8, 933-941). The ubiquity of this feature in various forms of ALS suggests that perhaps drugs that inhibit aberrant protein aggretation may provide new and improved treatment options. Thus, there is an urgent need to identify and develop drugs for the treatment of ALS.

SUMMARY OF THE INVENTION

The present invention encompasses the recognition that there exists a need new compounds and methods for treating patients with amyotrophic lateral sclerosis (ALS) or other neurodegenerative diseases characterized by the presence of aberrant protein aggregates.

The present invention relates to the identification of provided compounds and pharmaceutical compositions thereof to treat neurodegenerative diseases. Among other things, the present invention provides methods of treating amyotrophic lateral sclerosis (ALS) with provided compounds. Without wishing to be bound by any particular theory, provided compounds may be useful in the treatment of ALS or other neurodegenerative diseases where abnormal protein aggregation has been implicated, as they may prevent the aggregation of protein in a cell or limit the toxicity of such aggregates.

In one aspect, the invention provides compounds of the formula:

or a pharmaceutically acceptable salt thereof, or a tautomer thereof, wherein R⁰, R¹, R², R³, n, and p are as defined herein. In some embodiments, such compounds, or pharmaceutically acceptable salts thereof, or tautomers thereof, are used in the treatment of neurodegenerative diseases.

In another aspect, the invention provides methods for treating a subject with amyotrophic lateral sclerosis (ALS) or other neurodegenerative disease (e.g., Alzheimer's Disease, prion disease, or Huntington's Disease) by administering a therapeutically effective amount of an inventive compound, or a pharmaceutical composition thereof. In certain embodiments, the compound is of one of the classes described herein or is a species described herein. In another aspect, the invention provides methods for treating a subject with ALS or other neurodegenerative disease by administering both an inventive compound or pharmaceutical composition thereof, and a second therapeutic agent or pharmaceutical composition thereof. The two compounds and/or compositions may be administered as a combination composition comprising both compounds. Alternatively, the two compounds may be administered separately (e.g., as two different compositions) either simultaneously or sequentially.

The present invention also provides methods of identifying compounds that protect against the cytotoxic effects of abnormal protein aggregation. Additionally, the present invention provides methods of identifying compounds that prevent, inhibit, or reverse protein aggregation. In some embodiments, the inventive assay involves the use of PC12 cells expressing the protein SOD1. In certain embodiments, SOD1 is labeled with a detectable moiety (e.g., a fluorescent moiety). Assays may be high-throughput assays.

In another aspect, the present invention provides methods of inhibiting or reversing abnormal protein aggregation (e.g., SOD1 protein aggregates). Inhibiting or reversing abnormal protein aggregation may occur in vivo (e.g., in a subject as described herein) or in vitro (e.g., in a cell). In yet another aspect, the invention provides methods of protecting cells from the cytotoxic effects of aggregated protein (e.g., SOD1) using an inventive compound. Protection of cells may occur in vivo or in vitro. In some embodiments, protection occurs in vitro and the cells are PC12 cells. In another aspect, the invention provides methods of modulating proteasome activity in vivo or in vitro using a provided compound. In some embodiments, protection occurs in vitro, and the cells used are PC12 cells or HeLa cells. In certain embodiments, the cells are mammalian cells. In certain embodiments, the cells are in an organism (e.g., a mammal).

The present invention contemplates provided compounds for use in medicine.

All publications and patent documents cited in this application are incorporated herein by reference in their entirety.

Definitions

Aliphatic: The term “aliphatic” or “aliphatic group,” as used herein, means a straight-chain (i.e., unbranched) or branched, substituted or unsubstituted hydrocarbon chain that is completely saturated or that contains one or more units of unsaturation, or a monocyclic hydrocarbon or bicyclic hydrocarbon that is completely saturated or that contains one or more units of unsaturation, but which is not aromatic (also referred to herein as “carbocycle” “cycloaliphatic” or “cycloalkyl”), that has a single point of attachment to the rest of the molecule. Unless otherwise specified, aliphatic groups contain 1-20 aliphatic carbon atoms. In some embodiments, aliphatic groups contain 1-12 aliphatic carbon atoms. In some embodiments, aliphatic groups contain 1-6 aliphatic carbon atoms. In some embodiments, aliphatic groups contain 1-5 aliphatic carbon atoms. In other embodiments, aliphatic groups contain 1-4 aliphatic carbon atoms. In still other embodiments, aliphatic groups contain 1-3 aliphatic carbon atoms, and in yet other embodiments, aliphatic groups contain 1-2 aliphatic carbon atoms. In some embodiments, “cycloaliphatic” (or “carbocycle” or “cycloalkyl”) refers to a monocyclic C₃-C₆ hydrocarbon that is completely saturated or that contains one or more units of unsaturation, but which is not aromatic, that has a single point of attachment to the rest of the molecule. Suitable aliphatic groups include, but are not limited to, linear or branched, substituted or unsubstituted alkyl, alkenyl, alkynyl groups and hybrids thereof such as (cycloalkyl)alkyl, (cycloalkenyl)alkyl or (cycloalkyl)alkenyl.

Alkyl: As used herein, the term “alkyl” refers to saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups.

Alkylene: The term “alkylene” refers to a bivalent alkyl group. An “alkylene chain” is a polymethylene group, i.e., —(CH₂)_(n)—, wherein n is a positive integer, preferably from 1 to 20, 1 to 12, 1 to 6, from 1 to 4, from 1 to 3, from 1 to 2, or from 2 to 3. A substituted alkylene chain is a polymethylene group in which one or more methylene hydrogen atoms are replaced with a substituent. Suitable substituents include those described below for a substituted aliphatic group.

Alkenyl: As used herein, the term “alkenyl” refers to unsaturated aliphatic groups analogous in possible substitution to the alkyls described above, but that contain at least one double bond.

Alkenylene: As used herein, the term “alkenylene” refers to a bivalent alkenyl group. A substituted alkenylene chain is a polymethylene group containing at least one double bond in which one or more hydrogen atoms are replaced with a substituent. Suitable substituents include those described below for a substituted aliphatic group.

Alkynyl: As used herein, the term “alkynyl” refers to unsaturated aliphatic groups analogous in possible substitution to the alkyls described above, but that contain at least one triple bond.

Animal: As used herein, the term “animal” refers to any member of the animal kingdom. In some embodiments, “animal” refers to humans, at any stage of development. In some embodiments, “animal” refers to non-human animals, at any stage of development. In certain embodiments, the non-human animal is a mammal (e.g., a rodent, a mouse, a rat, a rabbit, a monkey, a dog, a cat, a sheep, cattle, a primate, and/or a pig). In some embodiments, animals include, but are not limited to, mammals, birds, reptiles, amphibians, fish, and/or worms. In some embodiments, an animal may be a transgenic animal, a genetically-engineered animal, and/or a clone.

Approximately: As used herein, the terms “approximately” or “about” in reference to a number are generally taken to include numbers that fall within a range of 5%, 10%, 15%, or 20% in either direction (greater than or less than) of the number unless otherwise stated or otherwise evident from the context (except where such number would be less than 0% or exceed 100% of a possible value). In some embodiments, use of the term “about” in reference to dosages means±5 mg/kg/day.

Aryl: The term “aryl” used alone or as part of a larger moiety as in “aralkyl,” “aralkoxy,” or “aryloxyalkyl,” refers to monocyclic and bicyclic ring systems having a total of five to fourteen ring members, wherein at least one ring in the system is aromatic and wherein each ring in the system contains three to seven ring members. In certain embodiments of the present invention, “aryl” refers to an aromatic ring system which includes, but not limited to, phenyl, biphenyl, naphthyl, anthracyl and the like, which may bear one or more substituents. Also included within the scope of the term “aryl,” as it is used herein, is a group in which an aromatic ring is fused to one or more non-aromatic rings, such as indanyl, phthalimidyl, naphthimidyl, phenanthridinyl, or tetrahydronaphthyl, and the like.

Arylalkyl: As used herein, the term “arylalkyl” refers to an aryl substituted alkyl group, wherein the terms “aryl” and “alkyl” are defined herein, and wherein the aryl group is attached to the alkyl group, which in turn is attached to the parent molecule. An exemplary arylalkyl group includes benzyl.

Characteristic portion: As used herein, the phrase a “characteristic portion” of a protein or polypeptide is one that contains a continuous stretch of amino acids, or a collection of continuous stretches of amino acids, that together are characteristic of a protein or polypeptide. Each such continuous stretch generally will contain at least two amino acids. Furthermore, those of ordinary skill in the art will appreciate that typically at least 5, 10, 15, or more amino acids are required to be characteristic of a protein. In general, a characteristic portion is one that, in addition to the sequence identity specified above, shares at least one functional characteristic with the relevant intact protein.

Characteristic sequence: A “characteristic sequence” is a sequence that is found in all members of a family of polypeptides or nucleic acids, and therefore can be used by those of ordinary skill in the art to define members of the family.

Effective amount: As used herein, an “effective amount” is an amount that achieves, or is expected to achieve, a desired result, and can be administered in one dose or in multiple doses. Compositions may be considered to contain an effective amount if they include a dose that is effective in the context of a dosing regimen, even if the composition as a single dose is not expected to be effective.

Heteroaryl: The term “heteroaryl,” used alone or as part of a larger moiety as in “heteroaralkyl” or “heteroarylalkoxy,” refers to monocyclic, bicyclic, and tricyclic ring systems having a total of five to fourteen ring members, wherein one or more ring in the system is aromatic, one or more ring in the system contains one or more heteroatoms, and wherein each ring in the system contains 3 to 7 ring members. The term “heteroatom” refers to nitrogen, oxygen, or sulfur, and includes any oxidized form of nitrogen or sulfur, and any quaternized form of a basic nitrogen. Heteroaryl groups include, without limitation, thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, and pteridinyl. The terms “heteroaryl” and “heteroar-,” as used herein, also include groups in which a heteroaromatic ring is fused to one or more aryl, cycloaliphatic, or heterocyclyl rings, where the radical or point of attachment is on the heteroaromatic ring. Nonlimiting examples include indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and pyrido[2,3-b]-1,4-oxazin-3(4H)-one. A heteroaryl group may be mono- or bicyclic. The term “heteroaryl” may be used interchangeably with the terms “heteroaryl ring,” “heteroaryl group,” or “heteroaromatic,” any of which terms include rings that are optionally substituted. The term “heteroaralkyl” refers to an alkyl group substituted by a heteroaryl, wherein the alkyl and heteroaryl portions independently are optionally substituted.

Heteroatom: The term “heteroatom” means one or more of oxygen, sulfur, nitrogen, phosphorus, or silicon (including, any oxidized form of nitrogen, sulfur, phosphorus, or silicon; the quaternized form of any basic nitrogen or; a substitutable nitrogen of a heterocyclic ring, for example N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl) or NR⁺ (as in N-substituted pyrrolidinyl)).

Heterocycle: As used herein, the terms “heterocycle,” “heterocyclyl,” “heterocyclic radical,” and “heterocyclic ring” are used interchangeably and refer to a stable 5- to 7-membered monocyclic or 7-10-membered bicyclic heterocyclic moiety that is either saturated or partially unsaturated, and having, in addition to carbon atoms, one or more, preferably one to four, heteroatoms, as defined above. When used in reference to a ring atom of a heterocycle, the term “nitrogen” includes a substituted nitrogen. As an example, in a saturated or partially unsaturated ring having 0-3 heteroatoms selected from oxygen, sulfur or nitrogen, the nitrogen may be N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl), or ⁺NR (as in N-substituted pyrrolidinyl).

A heterocyclic ring can be attached to its pendant group at any heteroatom or carbon atom that results in a stable structure and any of the ring atoms can be optionally substituted. Examples of such saturated or partially unsaturated heterocyclic radicals include, without limitation, tetrahydrofuranyl, tetrahydrothiophenyl pyrrolidinyl, piperidinyl, pyrrolinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, dioxolanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, and quinuclidinyl. The terms “heterocycle,” “heterocyclyl,” “heterocyclyl ring,” “heterocyclic group,” “heterocyclic moiety,” and “heterocyclic radical,” are used interchangeably herein, and also include groups in which a heterocyclyl ring is fused to one or more aryl, heteroaryl, or cycloaliphatic rings, such as indolinyl, 3H-indolyl, chromanyl, phenanthridinyl, or tetrahydroquinolinyl, where the radical or point of attachment is on the heterocyclyl ring. A heterocyclyl group may be mono- or bicyclic. The term “heterocyclylalkyl” refers to an alkyl group substituted by a heterocyclyl, wherein the alkyl and heterocyclyl portions independently are optionally substituted.

Intraperitoneal: The phrases “intraperitoneal administration” and “administered intraperitonealy” as used herein have their art-understood meaning referring to administration of a compound or composition into the peritoneum of a subject.

In vitro: As used herein, the term “in vitro” refers to events that occur in an artificial environment, e.g., in a test tube or reaction vessel, in cell culture, etc., rather than within an organism (e.g., animal, plant, and/or microbe).

In vivo: As used herein, the term “in vivo” refers to events that occur within an organism (e.g., animal, plant, and/or microbe).

Lower alkyl: The term “lower alkyl” refers to a C₁₋₄ straight or branched alkyl group. Exemplary lower alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl.

Lower haloalkyl: The term “lower haloalkyl” refers to a C₁₋₆ straight or branched alkyl group that is substituted with one or more halogen atoms.

Optionally substituted: As described herein, compounds of the invention may contain “optionally substituted” moieties. In general, the term “substituted,” whether preceded by the term “optionally” or not, means that one or more hydrogens of the designated moiety are replaced with a suitable substituent. Unless otherwise indicated, an “optionally substituted” group may have a suitable substituent at each substitutable position of the group, and when more than one position in any given structure may be substituted with more than one substituent selected from a specified group, the substituent may be either the same or different at every position. Combinations of substituents envisioned by this invention are preferably those that result in the formation of stable or chemically feasible compounds. The term “stable,” as used herein, refers to compounds that are not substantially altered when subjected to conditions to allow for their production, detection, and, in certain embodiments, their recovery, purification, and use for one or more of the purposes disclosed herein.

Unless otherwise indicated, suitable monovalent substituents on a substitutable carbon atom of an “optionally substituted” group are independently halogen; —(CH₂)₀₋₄R^(º); —(CH₂)₀₋₄OR^(º); —O(CH₂)₀₋₄R^(º), —O—(CH₂)₀₋₄C(O)OR^(º); —(CH₂)₀₋₄—CH(OR^(º))₂; —(CH₂)₀₋₄SR^(º); —(CH₂)₀₋₄Ph, which may be substituted with R^(º); —(CH₂)₀₋₄O(CH₂)₀₋₁Ph which may be substituted with R^(º); —CH═CHPh, which may be substituted with R^(º); —(CH₂)₀₋₄O(CH₂)₀₋₁-pyridyl which may be substituted with R^(º); —NO₂; —CN; —N₃; —(CH₂)₀₋₄N(R^(º))₂; —(CH₂)₀₋₄N(R^(º))C(O)R^(º); —N(R^(º))C(S)R^(º); —(CH₂)₀₋₄N(R^(º))C(O)NR^(º) ₂; —N(R^(º))C(S)NR^(º) ₂; —(CH₂)₀₋₄N(R^(º))C(O)OR^(º); —N(R^(º))N(R^(º))C(O)R^(º); —N(R^(º))N(R^(º))C(O)NR^(º) ₂; —N(R^(º))N(R^(º))C(O)OR^(º); —(CH₂)₀₋₄C(O)R^(º); —C(S)R^(º); —(CH₂)₀₋₄C(O)OR^(º); —(CH₂)₀₋₄C(O)SR^(º); —(CH₂)₀₋₄C(O)OSiR^(º) ₃; —(CH₂)₀₋₄OC(O)R^(º); —OC(O)(CH₂)₀₋₄SR—, SC(S)SR^(º); —(CH₂)₀₋₄SC(O)R^(º); —(CH₂)₀₋₄C(O)NR^(º) ₂; —C(S)NR^(º) ₂; —C(S)SR^(º); —SC(S)SR^(º), —(CH₂)₀₋₄OC(O)NR^(º) ₂; —C(O)N(OR^(º))R^(º); —C(O)C(O)R^(º); —C(O)CH₂C(O)R^(º); —C(NOR^(º))R^(º); —(CH₂)₀₋₄SSR^(º); —(CH₂)₀₋₄S(O)₂R^(º); —(CH₂)₀₋₄S(O)₂OR^(º); —(CH₂)₀₋₄OS(O)₂R^(º); —S(O)₂NR^(º) ₂; —(CH₂)₀₋₄S(O)R^(º); —N(R^(º))S(O)₂NR^(º) ₂; —N(R^(º))S(O)₂R^(º); —N(OR^(º))R^(º); —C(NH)NR^(º) ₂; —P(O)₂R^(º); —P(O)R^(º) ₂; —OP(O)R^(º) ₂; —OP(O)(OR^(º))₂; SiR^(º) ₃; —(C₁₋₄ straight or branched)alkylene)O—N(R^(º))₂; or —(C₁₋₄ straight or branched) alkylene)C(O)O—N(R^(º))₂, wherein each R^(º) may be substituted as defined below and is independently hydrogen, C₁₋₆ aliphatic, —CH₂Ph, —O(CH₂)₀₋₁Ph, —CH₂-(5-6 membered heteroaryl ring), or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or, notwithstanding the definition above, two independent occurrences of R^(º), taken together with their intervening atom(s), form a 3-12-membered saturated, partially unsaturated, or aryl mono- or bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, which may be substituted as defined below.

Unless otherwise indicated, suitable monovalent substituents on R^(º) (or the ring formed by taking two independent occurrences of R^(º) together with their intervening atoms), are independently halogen, —(CH₂)₀₋₂R^(●), -(haloR^(●)), —(CH₂)₀₋₂OH, —(CH₂)₀₋₂OR^(●), —(CH₂)₀₋₂CH(OR^(●))₂; —O(haloR^(●)), —CN, —N₃, —(CH₂)₀₋₂C(O)R^(●), —(CH₂)₀₋₂C(O)OH, —(CH₂)₀₋₂C(O)OR^(●), —(CH₂)₀₋₂SR^(●), —(CH₂)₀₋₂SH, —(CH₂)₀₋₂NH₂, —(CH₂)₀₋₂NHR^(●), —(CH₂)₀₋₂NR^(●) ₂, —NO₂, —SiR^(●) ₃, —OSiR^(●) ₃, —C(O)SR^(●), —(C₁₋₄ straight or branched alkylene)C(O)OR^(●), or —SSR^(●) wherein each R^(●) is unsubstituted or where preceded by “halo” is substituted only with one or more halogens, and is independently selected from C₁₋₄ aliphatic, —CH₂Ph, —O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. Suitable divalent substituents on a saturated carbon atom of R^(º) include ═O and ═S.

Unless otherwise indicated, suitable divalent substituents on a saturated carbon atom of an “optionally substituted” group include the following: ═O, ═S, ═NNR*₂, ═NNHC(O)R*, ═NNHC(O)OR*, ═NNHS(O)₂R*, ═NR*, ═NOR*, —O(C(R*₂))₂₋₃O—, or —S(C(R*₂))₂₋₃S—, wherein each independent occurrence of R* is selected from hydrogen, C₁₋₆ aliphatic which may be substituted as defined below, or an unsubstituted 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. Unless otherwise indicated, suitable divalent substituents that are bound to vicinal substitutable carbons of an “optionally substituted” group include: —O(CR*₂)₂₋₃O—, wherein each independent occurrence of R* is selected from hydrogen, C₁₋₆ aliphatic which may be substituted as defined below, or an unsubstituted 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Unless otherwise indicated, suitable substituents on the aliphatic group of R* include halogen, —R^(●), -(haloR^(●)), —OH, —OR^(●), —O(haloR^(●)), —CN, —C(O)OH, —C(O)OR^(●), —NH₂, —NHR^(●), —NR^(●) ₂, or —NO₂, wherein each R^(●) is unsubstituted or where preceded by “halo” is substituted only with one or more halogens, and is independently C₁₋₄ aliphatic, —CH₂Ph, —O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Unless otherwise indicated, suitable substituents on a substitutable nitrogen of an “optionally substituted” group include —R^(†), —NR^(†) ₂, —C(O)R^(†), —C(O)OR^(†), —C(O)C(O)R^(†), —C(O)CH₂C(O)R^(†), —S(O)₂R^(†), —S(O)₂NR^(†) ₂, —C(S)NR^(†) ₂, —C(NH)NR^(†) ₂, or —N(R^(†))S(O)₂R^(†); wherein each R^(†) is independently hydrogen, C₁₋₆ aliphatic which may be substituted as defined below, unsubstituted —OPh, or an unsubstituted 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or, notwithstanding the definition above, two independent occurrences of R^(†), taken together with their intervening atom(s) form an unsubstituted 3-12-membered saturated, partially unsaturated, or aryl mono- or bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Unless otherwise indicated, suitable substituents on the aliphatic group of R^(†) are independently halogen, —R^(●), -(haloR^(●)), —OH, —OR^(●), —O(haloR^(●)), —CN, —C(O)OH, —C(O)OR^(●), —NH₂, —NHR^(●), —NR^(●) ₂, or —NO₂, wherein each R^(●) is unsubstituted or where preceded by “halo” is substituted only with one or more halogens, and is independently C₁₋₄ aliphatic, —CH₂Ph, —O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Oral: The phrases “oral administration” and “administered orally” as used herein have their art-understood meaning referring to administration by mouth of a compound or composition.

Parenteral: The phrases “parenteral administration” and “administered parenterally” as used herein have their art-understood meaning referring to modes of administration other than enteral and topical administration, usually by injection, and include, without limitation, intravenous, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intraarticulare, subcapsular, subarachnoid, intraspinal, and intrasternal injection and infusion.

Partially unsaturated: As used herein, the term “partially unsaturated” refers to a ring moiety that includes at least one double or triple bond. The term “partially unsaturated” is intended to encompass rings having multiple sites of unsaturation, but is not intended to include aryl or heteroaryl moieties, as herein defined.

Patient: As used herein, the term “patient,” “subject,” or “test subject” refers to any organism to which a provided compound is administered in accordance with the present invention e.g., for experimental, diagnostic, prophylactic, and/or therapeutic purposes. Typical subjects include animals (e.g., mammals such as mice, rats, rabbits, non-human primates, and humans; insects; worms; etc.). In some embodiments, a subject may be suffering from, and/or susceptible to a disease, disorder, and/or condition (e.g., a neurodegenerative disease, a disease, disorder or condition associated with protein aggregation, ALS, etc.).

Pharmaceutically acceptable: The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.

Prodrug: A general, a “prodrug,” as that term is used herein and as is understood in the art, is an entity that, when administered to an organism, is metabolized in the body to deliver a therapeutic agent of interest. Various forms of “prodrugs” are known in the art. For examples of such prodrug derivatives, see:

-   a) Design of Prodrugs, edited by H. Bundgaard, (Elsevier, 1985) and     Methods in Enzymology, 42:309-396, edited by K. Widder, et al.     (Academic Press, 1985); -   b) A Textbook of Drug Design and Development, edited by     Krogsgaard-Larsen; -   c) Bundgaard, Chapter 5 “Design and Application of Prodrugs,” by H.     Bundgaard, p. 113-191 (1991); -   d) Bundgaard, Advanced Drug Delivery Reviews, 8:1-38 (1992); -   e) Bundgaard, et al., Journal of Pharmaceutical Sciences, 77:285     (1988); and -   f) Kakeya, et al., Chem. Pharm. Bull., 32:692 (1984).

The methods and structures described herein relating to the provided compounds also apply to pharmaceutically acceptable salts thereof.

Protecting group: The term “protecting group,” as used herein, is well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley & Sons, 1999, the entirety of which is incorporated herein by reference. Suitable amino-protecting groups include methyl carbamate, ethyl carbamante, 9-fluorenylmethyl carbamate (Fmoc), 9-(2-sulfo)fluorenylmethyl carbamate, 9-(2,7-dibromo)fluoroenylmethyl carbamate, 2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methyl carbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc), 2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate (Teoc), 2-phenylethyl carbamate (hZ), 1-(1-adamantyl)-1-methylethyl carbamate (Adpoc), 1,1-dimethyl-2-haloethyl carbamate, 1,1-dimethyl-2,2-dibromo ethyl carbamate (DB-t-BOC), 1,1-dimethyl-2,2,2-trichloroethyl carbamate (TCBOC), 1-methyl-1-(4-biphenylyl)ethyl carbamate (Bpoc), 1-(3,5-di-t-butylphenyl)-1-methylethyl carbamate (t-Bumeoc), 2-(2′- and 4′-pyridyl)ethyl carbamate (Pyoc), 2-(N,N-dicyclohexylcarboxamido)ethyl carbamate, t-butyl carbamate (BOC), 1-adamantyl carbamate (Adoc), vinyl carbamate (Voc), allyl carbamate (Alloc), 1-isopropylallyl carbamate (Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc), 8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyldithio carbamate, benzyl carbamate (Cbz), p-methoxybenzyl carbamate (Moz), p-nitobenzyl carbamate, p-bromobenzyl carbamate, p-chlorobenzyl carbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzyl carbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate, 2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate, 2-(p-toluenesulfonyl)ethyl carbamate, [2-(1,3-dithianyl)]methyl carbamate (Dmoc), 4-methylthiophenyl carbamate (Mtpc), 2,4-dimethylthiophenyl carbamate (Bmpc), 2-phosphonioethyl carbamate (Peoc), 2-triphenylphosphonioisopropyl carbamate (Ppoc), 1,1-dimethyl-2-cyanoethyl carbamate, m-chloro-p-acyloxybenzyl carbamate, p-(dihydroxyboryl)benzyl carbamate, 5-benzisoxazolylmethyl carbamate, 2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenyl carbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl carbamate, 3,4-dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methyl carbamate, phenothiazinyl-(10)-carbonyl derivative, N′-p-toluenesulfonylaminocarbonyl derivative, N′-phenylaminothiocarbonyl derivative, t-amyl carbamate, S-benzyl thiocarbamate, p-cyanobenzyl carbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentyl carbamate, cyclopropylmethyl carbamate, p-decyloxybenzyl carbamate, 2,2-dimethoxycarbonylvinyl carbamate, o-(N,N-dimethylcarboxamido)benzyl carbamate, 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate, 1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate, 2-furanylmethyl carbamate, 2-iodoethyl carbamate, isoborynl carbamate, isobutyl carbamate, isonicotinyl carbamate, p-(p′-methoxyphenylazo)benzyl carbamate, 1-methylcyclobutyl carbamate, 1-methylcyclohexyl carbamate, 1-methyl-1-cyclopropylmethyl carbamate, 1-methyl-1-(3,5-dimethoxyphenyl)ethyl carbamate, 1-methyl-1-(p-phenylazophenyl)ethyl carbamate, 1-methyl-1-phenylethyl carbamate, 1-methyl-1-(4-pyridyl)ethyl carbamate, phenyl carbamate, p-(phenylazo)benzyl carbamate, 2,4,6-tri-t-butylphenyl carbamate, 4-(trimethylammonium)benzyl carbamate, 2,4,6-trimethylbenzyl carbamate, formamide, acetamide, chloroacetamide, trichloroacetamide, trifluoroacetamide, phenylacetamide, 3-phenylpropanamide, picolinamide, 3-pyridylcarboxamide, N-benzoylphenylalanyl derivative, benzamide, p-phenylbenzamide, o-nitophenylacetamide, o-nitrophenoxyacetamide, acetoacetamide, (N′-dithiobenzyloxycarbonylamino)acetamide, 3-(p-hydroxyphenyl)propanamide, 3-(o-nitrophenyl)propanamide, 2-methyl-2-(o-nitrophenoxy)propanamide, 2-methyl-2-(o-phenylazophenoxy)propanamide, 4-chlorobutanamide, 3-methyl-3-nitrobutanamide, o-nitrocinnamide, N-acetylmethionine derivative, o-nitrobenzamide, o-(benzoyloxymethyl)benzamide, 4,5-diphenyl-3-oxazolin-2-one, N-phthalimide, N-dithiasuccinimide (Dts), N-2,3-diphenylmaleimide, N-2,5-dimethylpyrrole, N-1,1,4,4-tetramethyldisilylazacyclopentane adduct (STABASE), 5-substituted 1,3-dimethyl-1,3,5-triazacyclohexan-2-one, 5-substituted 1,3-dibenzyl-1,3,5-triazacyclohexan-2-one, 1-substituted 3,5-dinitro-4-pyridone, N-methylamine, N-allylamine, N-[2-(trimethylsilyl)ethoxy]methylamine (SEM), N-3-acetoxypropylamine, N-(1-isopropyl-4-nitro-2-oxo-3-pyroolin-3-yl)amine, quaternary ammonium salts, N-benzylamine, N-di(4-methoxyphenyl)methylamine, N-5-dibenzosuberylamine, N-triphenylmethylamine (Tr), N-[(4-methoxyphenyl)diphenylmethyl]amine (MMTr), N-9-phenylfluorenylamine (PhF), N-2,7-dichloro-9-fluorenylmethyleneamine, N-ferrocenylmethylamino (Fcm), N-2-picolylamino N′-oxide, N-1,1-dimethylthiomethyleneamine, N-benzylideneamine, N-p-methoxybenzylideneamine, N-diphenylmethylene amine, N-[(2-pyridyl)mesityl]methyleneamine, N—(N′,N′-dimethylaminomethylene)amine, N,N′-isopropylidenediamine, N-p-nitrobenzylideneamine, N-salicylideneamine, N-5-chlorosalicylideneamine, N-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine, N-cyclohexylideneamine, N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine, N-borane derivative, N-diphenylborinic acid derivative, N-[phenyl(pentacarbonylchromium- or tungsten)carbonyl]amine, N-copper chelate, N-zinc chelate, N-nitroamine, N-nitrosoamine, amine N-oxide, diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt), diphenylthiophosphinamide (Ppt), dialkyl phosphoramidates, dibenzyl phosphoramidate, diphenyl phosphoramidate, benzenesulfenamide, o-nitrobenzenesulfenamide (Nps), 2,4-dinitrobenzenesulfenamide, pentachlorobenzenesulfenamide, 2-nitro-4-methoxybenzenesulfenamide, triphenylmethylsulfenamide, 3-nitropyridinesulfenamide (Npys), p-toluenesulfonamide (Ts), benzenesulfonamide, 2,3,6,-trimethyl-4-methoxybenzenesulfonamide (Mtr), 2,4,6-trimethoxybenzenesulfonamide (Mtb), 2,6-dimethyl-4-methoxybenzenesulfonamide (Pme), 2,3,5,6-tetramethyl-4-methoxybenzenesulfonamide (Mte), 4-methoxybenzenesulfonamide (Mbs), 2,4,6-trimethylbenzenesulfonamide (Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds), 2,2,5,7,8-pentamethylchroman-6-sulfonamide (Pmc), methanesulfonamide (Ms), β-trimethylsilylethanesulfonamide (SES), 9-anthracenesulfonamide, 4-(4′,8′-dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS), benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.

Unless otherwise indicated, suitably protected carboxylic acids further include, but are not limited to, silyl-, alkyl-, alkenyl-, aryl-, and arylalkyl-protected carboxylic acids. Examples of suitable silyl groups include trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, triisopropylsilyl, and the like. Examples of suitable alkyl groups include methyl, benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, trityl, t-butyl, tetrahydropyran-2-yl. Examples of suitable alkenyl groups include allyl. Examples of suitable aryl groups include optionally substituted phenyl, biphenyl, or naphthyl. Examples of suitable arylalkyl groups include optionally substituted benzyl (e.g., p-methoxybenzyl (MPM), 3,4-dimethoxybenzyl, O-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl), and 2- and 4-picolyl.

Unless otherwise indicated, suitable hydroxyl protecting groups include methyl, methoxylmethyl (MOM), methylthiomethyl (MTM), t-butylthiomethyl, (phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM), p-methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl (p-AOM), guaiacolmethyl (GUM), t-butoxymethyl, 4-pentenyloxymethyl (POM), siloxymethyl, 2-methoxyethoxymethyl (MEM), 2,2,2-trichloroethoxymethyl, bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl (SEMOR), tetrahydropyranyl (THP), 3-bromotetrahydropyranyl, tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl (MTHP), 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranyl S,S-dioxide, 1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl (CTMP), 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl, 2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl, 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl, 1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoro ethyl, 2,2,2-trichloroethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl, t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl, benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl, p-phenylbenzyl, 2-picolyl, 4-picolyl, 3-methyl-2-picolyl N-oxido, diphenylmethyl, p,p′-dinitrobenzhydryl, 5-dibenzosuberyl, triphenylmethyl, α-naphthyldiphenylmethyl, p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl, tri(p-methoxyphenyl)methyl, 4-(4′-bromophenacyloxyphenyl)diphenylmethyl, 4,4′,4″-tris(4,5-dichlorophthalimidophenyl)methyl, 4,4′,4″-tris(levulinoyloxyphenyl)methyl, 4,4′,4″-tris(benzoyloxyphenyl)methyl, 3-(imidazol-1-yl)bis(4′,4″-dimethoxyphenyl)methyl, 1,1-bis(4-methoxyphenyl)-1′-pyrenylmethyl, 9-anthryl, 9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl, 1,3-benzodithiolan-2-yl, benzisothiazolyl S,S-dioxido, trimethylsilyl (TMS), triethylsilyl (TES), triisopropylsilyl (TIPS), dimethylisopropylsilyl (IPDMS), diethylisopropylsilyl (DEIPS), dimethylthexylsilyl, t-butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl (TBDPS), tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl, diphenylmethylsilyl (DPMS), t-butylmethoxyphenylsilyl (TBMPS), formate, benzoylformate, acetate, chloroacetate, dichloroacetate, trichloroacetate, trifluoroacetate, methoxyacetate, triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate, 3-phenylpropionate, 4-oxopentanoate (levulinate), 4,4-(ethylenedithio)pentanoate (levulinoyldithioacetal), pivaloate, adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate, 2,4,6-trimethylbenzoate (mesitoate), alkyl methyl carbonate, 9-fluorenylmethyl carbonate (Fmoc), alkyl ethyl carbonate, alkyl 2,2,2-trichloroethyl carbonate (Troc), 2-(trimethylsilyl)ethyl carbonate (TMSEC), 2-(phenylsulfonyl)ethyl carbonate (Psec), 2-(triphenylphosphonio) ethyl carbonate (Peoc), alkyl isobutyl carbonate, alkyl vinyl carbonate alkyl allyl carbonate, alkyl p-nitrophenyl carbonate, alkyl benzyl carbonate, alkyl p-methoxybenzyl carbonate, alkyl 3,4-dimethoxybenzyl carbonate, alkyl o-nitrobenzyl carbonate, alkyl p-nitrobenzyl carbonate, alkyl S-benzyl thiocarbonate, 4-ethoxy-1-napththyl carbonate, methyl dithiocarbonate, 2-iodobenzoate, 4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate, 2-formylbenzenesulfonate, 2-(methylthiomethoxy)ethyl, 4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate, 2,6-dichloro-4-methylphenoxyacetate, 2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate, 2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate, isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate, o-(methoxycarbonyl)benzoate, α-naphthoate, nitrate, alkyl N,N,N′,N′-tetramethylphosphorodiamidate, alkyl N-phenylcarbamate, borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate, sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate (Ts). For protecting 1,2- or 1,3-diols, the protecting groups include methylene acetal, ethylidene acetal, 1-t-butylethylidene ketal, 1-phenylethylidene ketal, (4-methoxyphenyl)ethylidene acetal, 2,2,2-trichloroethylidene acetal, acetonide, cyclopentylidene ketal, cyclohexylidene ketal, cycloheptylidene ketal, benzylidene acetal, p-methoxybenzylidene acetal, 2,4-dimethoxybenzylidene ketal, 3,4-dimethoxybenzylidene acetal, 2-nitrobenzylidene acetal, methoxymethylene acetal, ethoxymethylene acetal, dimethoxymethylene ortho ester, 1-methoxyethylidene ortho ester, 1-ethoxyethylidine ortho ester, 1,2-dimethoxyethylidene ortho ester, α-methoxybenzylidene ortho ester, 1-(N,N-dimethylamino)ethylidene derivative, α-(N,N′-dimethylamino)benzylidene derivative, 2-oxacyclopentylidene ortho ester, di-t-butylsilylene group (DTBS), 1,3-(1,1,3,3-tetraisopropyldisiloxanylidene) derivative (TIPDS), tetra-t-butoxydisiloxane-1,3-diylidene derivative (TBDS), cyclic carbonates, cyclic boronates, ethyl boronate, and phenyl boronate.

Protein: As used herein, the term “protein” refers to a polypeptide (i.e., a string of at least two amino acids linked to one another by peptide bonds). In some embodimments, proteins include only naturally-occurring amino acids. In some embodiments, proteins include one or more non-naturally-occurring amino acids (e.g., moieties that form one or more peptide bonds with adjacent amino acids). In some embodiments, one or more residues in a protein chain contains a non-amino-acid moiety (e.g., a glycan, etc). In some embodiments, a protein includes more than one polypeptide chain, for example linked by one or more disulfide bonds or associated by other means. In some embodiments, proteins contain L-amino acids, D-amino acids, or both; in some embodiments, proteins contain one or more amino acid modifications or analogs known in the art. Useful modifications include, e.g., terminal acetylation, amidation, methylation, etc. The term “peptide” is generally used to refer to a polypeptide having a length of less than about 100 amino acids, less than about 50 amino acids, less than 20 amino acids, or less than 10 amino acids. In some embodiments, proteins are antibodies, antibody fragments, biologically active portions thereof, and/or characteristic portions thereof.

Provided compound: The term “provided compound,” as used herein, refers to a compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein: p is 1-2;

designates a single or double bond, wherein one

is a single bond and one

is a double bond;

-   each R¹ is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R,     —N(R)₂, —CN, —NO₂—NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR,     —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R,     —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, or an optionally substituted 3-8     membered saturated, partially unsaturated, or aryl monocyclic ring     having 0-4 heteroatoms independently selected from nitrogen, oxygen,     or sulfur, or an optionally substituted 8-10 membered saturated,     partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms     independently selected from nitrogen, oxygen, or sulfur; or     -   two R¹ groups are taken together to form

-   -    wherein:         -   X is N or C;         -   each R⁵ is independently —R, —OR, —SR, —S(O)R, —SO₂R,             —OSO₂R, —N(R)₂, —CN, —NO₂—NRC(O)R, —NRC(O)(CO)R,             —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR,             —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂,             or a 3-8 membered saturated, partially unsaturated, or aryl             monocyclic ring having 0-4 heteroatoms independently             selected from nitrogen, oxygen, or sulfur, or an 8-10             membered saturated, partially unsaturated, or aryl bicyclic             ring having 0-4 heteroatoms independently selected from             nitrogen, oxygen, or sulfur, wherein R⁵ is optionally             substituted with 1-5 R groups;

-   each R is independently hydrogen, halogen, optionally substituted     C₁₋₂₀ aliphatic, optionally substituted C₁₋₂₀ heteroaliphatic,     optionally substituted phenyl, optionally substituted arylalkyl, or     two R on the same nitrogen are taken together to form a 5-6 membered     saturated, partially saturated, or aryl ring having 1-3 heteroatoms     independently selected from nitrogen, oxygen, and sulfur, or two R     on the same carbon or on adjacent carbons are optionally taken     together to form a 3-6 membered saturated cycloalkyl or fused     monocyclic ring containing 0-2 heteroatoms independently selected     from nitrogen, oxygen, and sulfur;

-   n is 0-1;

-   each R² and R³ are independently —R, —OR, —SR, —S(O)R, —SO₂R,     —OSO₂R, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂,     a suitable amino protecting group, or an optionally substituted 3-8     membered saturated, partially unsaturated, or aryl monocyclic ring     having 0-4 heteroatoms independently selected from nitrogen, oxygen,     or sulfur, or an optionally substituted 8-10 membered saturated,     partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms     independently selected from nitrogen, oxygen, or sulfur;

-   R⁰ is R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, N(R)₂, —NRC(O)R,     —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R,     —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂,     —OC(O)N(R)₂, or

-    wherein:     -   L is a valence bond or a bivalent saturated or partially         unsaturated C₁₋₁₀ hydrocarbon chain, wherein 1-4 methylene units         of L are optionally and independently replaced by —O—, —S—,         —C(O)—, —OC(O)—, —C(O)O—, —OC(O)O—, —S(O)—, —S(O)₂—, —OSO₂O—,         —N(R)C(O)—, —C(O)NR—, —N(R)C(O)O—, —OC(O)NR—, —N(R)C(O)NR—,         —N(R⁶)—, or -Cy-, and wherein L is optionally substituted with         1-4 R groups; wherein:         -   each -Cy- is independently a bivalent optionally substituted             saturated, partially unsaturated, or aromatic monocyclic or             bicyclic ring selected from a 6-10 membered arylene, a 5-10             membered heteroarylene having 1-4 heteroatoms independently             selected from oxygen, nitrogen, or sulfur, a 3-8 membered             carbocyclylene, or a 3-10 membered heterocyclylene having             1-4 heteroatoms independently selected from oxygen,             nitrogen, or sulfur;         -   R⁶ is —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —C(O)R, —C(O)OR,             —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, a suitable amino             protecting group, or an optionally substituted 3-8 membered             saturated, partially unsaturated, or aryl monocyclic ring             having 0-4 heteroatoms independently selected from nitrogen,             oxygen, or sulfur, or an optionally substituted 8-10             membered saturated, partially unsaturated, or aryl bicyclic             ring having 0-4 heteroatoms independently selected from             nitrogen, oxygen, or sulfur;     -   Ring A is a 3-8 membered saturated, partially unsaturated, or         aryl monocyclic ring optionally containing 0-4 heteroatoms         independently selected from nitrogen, oxygen, or sulfur, or an         8-10 membered saturated, partially unsaturated, or aryl bicyclic         ring optionally containing 0-4 heteroatoms independently         selected from nitrogen, oxygen, or sulfur, and wherein Ring A is         optionally substituted with occurrences of R⁴;         -   m is 0-5; and     -   each R⁴ is independently —R, —OR, —SR, —CN, —S(O)R, —SO₂R,         —OSO₂R, —N(R)₂, —NO₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂,         —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR,         —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, or a 3-8 membered         saturated, partially unsaturated, or aryl monocyclic ring         optionally containing 0-4 heteroatoms independently selected         from nitrogen, oxygen, or sulfur.

In some embodiments, the term “provided compound” may encompass prodrugs and/or esters of compounds of formula I. As discussed herein, provided compounds may be provided in salt form. In particular, in some embodiments, a provided compound is provided as a pharmaceutically acceptable salt of a compound of formula I.

Provided compounds may exist in particular geometric or stereoisomeric forms. The present invention contemplates all such compounds, including cis- and trans-isomers, R- and S-enantiomers, diastereomers, (D)-isomers, (L)-isomers, the racemic mixtures thereof, and other mixtures thereof, as falling within the scope of the invention. Additional asymmetric carbon atoms may be present in a substituent such as an alkyl group. All such isomers, as well as mixtures thereof, are intended to be included in this invention. That is, in some embodiments, the present invention provides isolated single isomers. In some embodiments, the present invention provides mixtures of two or more isomers. In certain embodiments, the present invention relates to a provided compound represented by any of the structures outlined herein, wherein the compound is provided as a single stereoisomer.

The terms acid or base addition salt also comprise the hydrates and the solvent addition forms which the compounds are able to form. Examples of such forms are, e.g., hydrates, alcoholates and the like.

Contemplated equivalents of the compounds described above include compounds which otherwise correspond thereto, and which have the same general properties thereof, wherein one or more simple variations of substituents are made which do not adversely affect the efficacy of the compound. In general, the compounds of the present invention may be prepared by the methods illustrated in the general reaction schemes as, for example, described below, or by modifications thereof, using readily available starting materials, reagents and conventional synthesis procedures. In these reactions, it is also possible to make use of variants, which are in themselves known, but are not mentioned here.

Stereochemically isomeric forms: The phrase “stereochemically isomeric forms,” as used herein, refers to different compounds made up of the same atoms bonded by the same sequence of bonds but having different three-dimensional structures which are not interchangeable. In some embodiments of the invention, chemical compositions may be provided as pure preparations of individual stereochemically isomeric forms of a compound; in some embodiments, chemical compositions may be provided that are or include mixtures of two or more stereochemically isomeric forms of the compound. In certain embodiments, such mixtures contain equal amounts of different stereochemically isomeric forms; in certain embodiments, such mixtures contain different amounts of at least two different stereochemically isomeric forms. In some embodiments, a chemical composition may contain all diastereomers and/or enantiomers of the compound. In some embodiments, a chemical composition may contain less than all diastereomers and/or enantiomers of a compound. Unless otherwise indicated, the present invention encompasses all stereochemically isomeric forms of relevant compounds, whether in pure form or in admixture with one another. If a particular enantiomer of a compound of the present invention is desired, it may be prepared, for example, by asymmetric synthesis, or by derivation with a chiral auxiliary, where the resulting diastereomeric mixture is separated and the auxiliary group cleaved to provide the pure desired enantiomers. Alternatively, where the molecule contains a basic functional group, such as amino, diastereomeric salts are formed with an appropriate optically-active acid, and resolved, for example, by fractional crystallization.

Substantially: As used herein, the term “substantially” refers to the qualitative condition of exhibiting total or near-total extent or degree of a characteristic or property of interest. One of ordinary skill in the biological arts will understand that biological and chemical phenomena rarely, if ever, go to completion and/or proceed to completeness or achieve or avoid an absolute result. The term “substantially” is therefore used herein to capture the potential lack of completeness inherent in many biological and/or chemical phenomena.

Suffering from: An individual who is “suffering from” a disease, disorder, and/or condition has been diagnosed with and/or displays one or more symptoms of a disease, disorder, and/or condition.

Susceptible to: An individual who is “susceptible to” a disease, disorder, and/or condition is one who has a higher risk of developing the disease, disorder, and/or condition than does a member of the general public. In some embodiments, an individual who is susceptible to a disease, disorder and/or condition may not have been diagnosed with the disease, disorder, and/or condition. In some embodiments, an individual who is susceptible to a disease, disorder, and/or condition may exhibit symptoms of the disease, disorder, and/or condition. In some embodiments, an individual who is susceptible to a disease, disorder, and/or condition may not exhibit symptoms of the disease, disorder, and/or condition. In some embodiments, an individual who is susceptible to a disease, disorder, and/or condition will develop the disease, disorder, and/or condition. In some embodiments, an individual who is susceptible to a disease, disorder, and/or condition will not develop the disease, disorder, and/or condition.

Tautomeric forms: The phrase “tautomeric forms,” as used herein, is used to describe different isomeric forms of organic compounds that are capable of facile interconversion. Tautomers may be characterized by the formal migration of a hydrogen atom or proton, accompanied by a switch of a single bond and adjacent double bond. In some embodiments, tautomers may result from prototropic tautomerism (i.e., the relocation of a proton). In some embodiments, tautomers may result from valence tautomerism (i.e., the rapid reorganization of bonding electrons). All such tautomeric forms are intended to be included within the scope of the present invention. In some embodiments, tautomeric forms of a compound exist in mobile equilibrium with each other, so that attempts to prepare the separate substances results in the formation of a mixture. In some embodiments, tautomeric forms of a compound are separable and isolatable compounds. In some embodiments of the invention, chemical compositions may be provided that are or include pure preparations of a single tautomeric form of a compound. In some embodiments of the invention, chemical compositions may be provided as mixtures of two or more tautomeric forms of a compound. In certain embodiments, such mixtures contain equal amounts of different tautomeric forms; in certain embodiments, such mixtures contain different amounts of at least two different tautomeric forms of a compound. In some embodiments of the invention, chemical compositions may contain all tautomeric forms of a compound. In some embodiments of the invention, chemical compositions may contain less than all tautomeric forms of a compound. In some embodiments of the invention, chemical compositions may contain one or more tautomeric forms of a compound in amounts that vary over time as a result of interconversion. Unless otherwise indicated, the present invention encompasses all tautomeric forms of relevant compounds, whether in pure form or in admixture with one another.

Therapeutic agent: As used herein, the phrase “therapeutic agent” refers to any agent that, when administered to a subject, has a therapeutic effect and/or elicits a desired biological and/or pharmacological effect. In some embodiments, a therapeutic agent is any substance that can be used to alleviate, ameliorate, relieve, inhibit, prevent, delay onset of, reduce severity of, and/or reduce incidence of one or more symptoms or features of a disease, disorder, and/or condition.

Therapeutically effective amount: As used herein, the term “therapeutically effective amount” means an amount of a substance (e.g., a therapeutic agent, composition, and/or formulation) that elicits a desired biological response when administered as part of a therapeutic regimen. In some embodiments, a therapeutically effective amount of a substance is an amount that is sufficient, when administered to a subject suffering from or susceptible to a disease, disorder, and/or condition, to treat, diagnose, prevent, and/or delay the onset of the disease, disorder, and/or condition. As will be appreciated by those of ordinary skill in this art, the effective amount of a substance may vary depending on such factors as the desired biological endpoint, the substance to be delivered, the target cell or tissue, etc. For example, the effective amount of compound in a formulation to treat a disease, disorder, and/or condition is the amount that alleviates, ameliorates, relieves, inhibits, prevents, delays onset of, reduces severity of and/or reduces incidence of one or more symptoms or features of the disease, disorder, and/or condition. In some embodiments, a therapeutically effective amount is administered in a single dose; in some embodiments, multiple unit doses are required to deliver a therapeutically effective amount. In some embodiments, a composition may be considered to include a therapeutically effective amount of a provided compound when it includes an amount that is effective when administered as part of a dosing regimen even if a single dose (i.e., only the amount in the composition) alone is not expected to be effective.

Treat: As used herein, the term “treat,” “treatment,” or “treating” refers to any method used to partially or completely alleviate, ameliorate, relieve, inhibit, delay onset of, reduce severity of, and/or reduce incidence of one or more symptoms or features of a disease, disorder, and/or condition; in some embodiments, treatment prevents one or more symptoms of features of the disease, disorder, or condition. Treatment may be administered to a subject who does not exhibit signs of a disease, disorder, and/or condition. In some embodiments, treatment may be administered to a subject who exhibits only early signs of the disease, disorder, and/or condition, for example for the purpose of decreasing the risk of developing pathology associated with the disease, disorder, and/or condition.

Systemic: The phrases “systemic administration,” “administered systemically,” “peripheral administration,” and “administered peripherally” as used herein have their art-understood meaning referring to administration of a compound or composition such that it enters the recipient's system.

Unsaturated: The term “unsaturated,” as used herein, means that a moiety has one or more units of unsaturation.

For purposes of this invention, the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 67th Ed., 1986-87, inside cover.

The methods and structures described herein relating to compounds and compositions of the invention also apply to the pharmaceutically acceptable acid or base addition salts and all stereoisomeric forms of these compounds and compositions.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1. Proteasome inhibition is selectively toxic to PC12 cells expressing mutant G93A SOD1. Cell survival was determined using the viability stain calcein-AM. At 24 hours, treatment with 100 nM MG132 shows no toxicity against any of the cell lines although large numbers of aggregates are seen in the G85R SOD1 cell lines (panel A). Treatment with 100 nM MG132 is selectively toxic to the G93A SOD1 cell line after 48 hours (panel B). Washing of the cells at 24 hours to remove the compound does not reverse toxicity to the G93A SOD1 cell line suggesting that an irreversible toxic event, potentially related the aggregation of G93A SOD1, has been triggered prior to wash out (panel C).

FIG. 2. Radicicol protects PC12 cells expressing mutant G93A SOD1 from the toxic effects of proteasome inhibitor MG132.

FIG. 3. Mutant but not wild type SOD1 aggregates in cells treated with the proteasome inhibitor MG132. Fluorescence micrographs of PC12 cells expressing YFP tagged wild type (WT), G93A mutant (G93A), and G85R mutant (G85R)SOD1 proteins. The micrographs show the effects of treating cells with 200 nM MG132 for 24 hours (untreated cells are shown in insets on left). The wild type SOD1 expressing cells are unaffected while cells expressing mutant SOD1 show large perinuclear aggregates.

FIG. 4. Radicicol decreases mutant SOD1 aggregation induced by proteasome inhibitor MG132. Fluorescence micrographs of PC12 cells expressing YFP tagged G93A SOD1 (left) or G85R SOD1 (right) proteins. The cells were untreated, treated with 200 nM MG132 to induce protein aggregation, or co-treated with MG132 and radicicol for 24 hours. Without radicicol treatment, cells show large perinuclear aggregates. The aggregates are reduced in radicicol-treated cells. While the behavior of the two cell lines is generally similar, G85R SOD1 cells show ‘brighter’ aggregates and more contrast between the aggregates and the cytoplasm.

FIG. 5. Automated detection of mutant SOD1 aggregates. Left: compound microscope fluorescence micrographs of the same G85R SOD1 cells using GFP filter set to image the SOD1-YFP aggregates (top) and the TRITC filter set to image iT-WGA plasma membrane (bottom). Right: Aggregate detection from the Cellomics Arrayscan 3.5 using spot detector software to image cells with Image-iT in channel 1 and SOD1-YFP aggregates in channel 2. Data are expressed as spot count (aggregates) per object (cell).

FIG. 6. Arylsulfanyl pyrazolones fail to induce heat shock response in Hsp 70 promotor assays. HeLa hse-luc cells were treated with arylsulfanyl pyrazolones (1 μM-100 μM), celestrol (1 μM-5 μM), or CdCl2 (10 μM-100 μM), for 8 h and activation of the heat shock response determined by HSP70 promoter activity.

FIG. 7. Arylsulfanyl pyrazolones prevent MG132-induced accumulation of Ubi-YFP. HeLa cells were co-transfected with Ubi-YFP and CMV-CFP plasmids, treated with 1 μM MG132 and 25 μM arylsulfanyl pyrazolones and Ubi-YFP fluorescence intensity normalized to CFP.

FIG. 8. Brain standard curve for CMB-087229.

FIG. 9. Plasma standard curve for CMB-087229.

FIG. 10. Plasma standard curve for CMB-087229.

FIG. 11. Structures of compounds used in the rat liver microsomal stability study of TC-I-16.

FIG. 12. Minaprine 0-20 minutes HADPH dependent rat liver microsomal stability.

FIG. 13. TC-I-165 0-20 minutes HADPH dependent rat liver microsomal stability.

FIG. 14. Structures of TC-I-165 metabolite candidates (sulfoxide metabolite candidate TC-II-68 and sulfone metabolite candidate TC-II-70).

FIG. 15. HPLC trace of TC-I-165 [0 min NADPH (tube 1)].

FIG. 16. HPLC trace of TC-I-165 [5 min NADPH (tube 2)] and a new peak with a retention time of 5.900 minutes.

FIG. 17. HPLC trace of TC-I-165 [60 min NADPH (tube 1)] and a new peak with a retention time of 5.917 minutes.

FIG. 18. HPLC trace of TC-II-68 [10 μM standard solution (tube 1)] and a new peak with a retention time of 5.933 minutes.

FIG. 19. HPLC trace of TC-II-70 [10 μM standard solution (tube 2)] and a new peak with a retention time of 11.000 minutes.

FIG. 20. Structures of compounds used in the rat liver microsomal stability study of TC-II-70.

FIG. 21. NADPH dependent rat liver microsomal stability study of TC-II-70.

FIG. 22. NADPH dependent rat liver microsomal stability study of minaprine.

FIG. 23. NADPH dependent rat liver microsomal stability study of warfarin.

FIG. 24. Active arylsulfanyl pyrazolones

FIG. 25. Preliminary SAR of selected arylsulfanylpyrazolones.

FIG. 26. Synthesis of arylsulfanylpyrazolones (Scheme 1).

FIG. 27. Synthesis of arylsulfanylpyrazolones (Scheme 2).

FIG. 28. Kaplan-Meier survival curve for dose response using CMB-087229 in G93A SOD1 ALS mice. A 13.4% extension in survival at the highest dose (20 mg/kg) with significance at p<0.05 was observed.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THE INVENTION

Imbalances in protein homeostasis are often associated with protein misfolding and/or protein conformational changes that lead to protein aggregation and formation of protein inclusion bodies. Many neurodegenerative diseases, including the polyglutamine (polyQ)-repeat diseases, Alzheimer's disease, Parkinson's disease, prion diseases, and ALS, are characterized by the appearance of damaged and aggregated proteins, including huntingtin, polyQ proteins, amyloid A prion (PrP and Sup35) fibrils, and mutant SOD1 (Taylor et al., Science 2002, 296(5575), 1991-1995; Ross, C. A., Neuron. 1997, 19(6), 1147-1150; Perutz, M. F., Brain Res. Bull. 1999, 50(5-6), 467; and Kopito et al., Nat. Cell Bio. 2000, 2(11), E207-E209). The fact that such diverse proteins form aggregates in patients with distinct neurological diseases suggests that a common molecular etiology may contribute to the neuropathology in these diseases and that, perhaps, protein misfolding and the subsequent appearance of protein aggregates are early events that play a role in neuronal toxicity in multiple human neurological diseases (On, H. T., Genes. Dev. 2001, 15(8), 925-932; Ikeda et al., Nat. Genet. 1996, 13(2), 196-202; DiFiglia et al., Science 1997, 277(5334), 1990-1993; Davies et al., Cell 1997, 90(3), 537-548; and Koo et al., Proc. Natl. Acad. Sci. USA. 1999, 96(18), 9989-9990).

One model for the molecular basis of these neurodegenerative diseases is that insoluble protein aggregates associate and interfere with the activity of other critical soluble cellular proteins, and that loss of function of these diverse proteins has serious negative consequences on cellular function. Affected proteins could include ubiquitin, components of the proteasome, components of the cytoskeleton, transcription factors (TBP (i.e., TATA binding protein), EYA (i.e., Eyes Absent protein), CBP (i.e., CREB binding protein), and molecular chaperones Hsc-70, Hsp-70, Hdj-1, and Hdj-2 (Davies et al., Cell 1997, 90(3), 537-548; Ross, C. A., Neuron. 2002, 35(5), 819-822; Cummings et al., Nat. Genet. 1998, 19(2) 148-154; Perez et al., J. Cell Biol. 1998, 143(6), 1457-1470; Kazantsev et al., Proc. Natl. Acad. Sci. USA. 1999, 96(20), 11404-11409; Jana et al., Hum. Mol. Genet. 2001, 10(10), 1049-1059; Nucifora et al., Science 2001, 291(5512) 2423-2428; and Suhr et al., J. Cell Biol. 2001, 153(2), 283-294). Recent studies showed that TBP and CBP are irreversibly sequestered in polyQ/huntington aggregates, while the chaperone Hsp70 is transiently associated with the surface (Chai et al., Proc. Natl. Acad. Sci. USA. 2002, 99(14), 9310-9315; Kim et al., Nat. Cell. Biol. 2002, 4(10), 826-31). Sequestration of CBP into polyglutamine aggregates is linked directly with loss of cellular function in neuronal cells, and overexpression of CBP suppressed polyQ toxicity (Nucifora et al., Science 2001, 291(5512) 2423-2428). Furthermore, expression of polyglutamine proteins in C. elegans causes other metastable proteins to lose function. Thus, a single aggregation-prone protein may be able to destabilize protein homeostasis in otherwise normal cells (Gidalevitz et al., Science 2006, 311(5766) 1471-1474). These studies indicate that the sequestration of essential soluble cellular proteins in insoluble protein aggregates could play a significant role in the neuropathology and neurotoxicity in ALS and related diseases.

It is also possible that the cellular mechanism(s) that remove misfolded or damaged proteins (Morimoto, R. I., Cell 2002, 110(3), 281-284; Horwich et al., Cell 1997, 89(4), 499-510; and Nollen et al., J. Cell. Sci. 2002, 115(Pt 14) 2809-2816) are overwhelmed in neurodegenerative diseases due to the presence of abundant protein aggregates. The activity of molecular chaperones is one of the most important mechanisms to prevent and/or rescue protein misfolding and aggregation. Molecular chaperones are a large and diverse protein family which includes Hsp104, Hsp90, Hsp70, dnaJ (Hsp40), immunophilins (Cyp40, FKBP), Hsp60 (chaperonins), the small heat shock proteins, and components of the steroid aporeceptor complex (p23, Hip, Hop, Bag1) (Gething, M. J., Nature 1997, 388(6640) 329-331; Bakau, B., Amsterdam: Harwood Academic Publishers. 1999, 690). They ensure proper protein folding by preventing hydrophobic surfaces from interacting with each other, by enhancing protein refolding, and, when necessary, by stimulating protein degradation to remove misfolded proteins that tend to aggregate (Horwich et al., Cell 1997, 89(4), 499-510; Bakau, B., Amsterdam: Harwood Academic Publishers. 1999, 690; Schroder et al., Embo. J. 1993, 12(11), 4137-4144; Parsell et al., Nature 1994, 372(6505), 475-478; Hartl, F. U., Nature 1996, 381(6583) 571-579; and Morimoto et al., Nat. Biotechnol. 1998, 16(9), 833-838). Accordingly, overexpression of molecular chaperones can suppress the toxicity of mutant huntingtin, α-synuclein, and SOD1 (Sakahira et al., Proc. Natl. Acad. Sci. USA. 2002, 99 Suppl 4, 6412-6418; Stenoien et al., Hum. Mol. Genet. 1999, 8(5), 731-741; Warrick et al., Nat. Genet. 1999, 23(4), 425-428; Carmichael et al., Proc. Natl. Acad. Sci. USA. 2000, 97(17), 9701-9705; Takeuchi et al., Brain Res. 2002, 949(1-2), 11-22; Auluck et al., Science 2002, 295 (5556), 865-868; and Bailey et al., Hum. Mol. Genet. 2002, 11(5), 515-523). Recently, non-chaperone proteins were identified that also suppress toxicity associated with protein aggregation (Kazemi-Esfarjani et al., Science 2000, 287(5459), 1837-1840; and Kazemi-Esfarjani et al., Hum. Mol. Genet. 2002, 11(21), 2657-2672).

The chaperone system is a highly appealing therapeutic target, because multiple small molecular weight modulators of chaperone activity have already been identified, two of which are active in a mouse model of ALS (Westerheide et al., J. Biol. Chem. 2005, 280(39), 33097-33100; Kieran et al., Nat. Med. 2004, 10(4), 402-405; and Traynor et al., Neurology 2006, 67(1), 20-27). Accordingly, recent analyses identified protein folding/misfolding and protein aggregation as a relevant therapeutic target for neurodegenerative diseases (Pasinelli et al., Nat. Rev. Neurosci. 2006, 7(9), 710-723; Lansbury et al., Nature 2006, 443(7113), 774-9; Rubinsztein et al., Nature 2006, 443(7113), 780-786).

Provided Compounds

The present invention provides compounds and methods for treating patients with amyotrophic lateral sclerosis (ALS) or other neurodegenerative diseases characterized by the presence of aberrant protein aggregates. Without wishing to be bound by any particular theory or mechanism of action, compounds and methods of the invention are useful in inhibiting or reversing abnormal protein aggregation or reducing the toxicity of protein aggregation (e.g., SOD1). In certain embodiments, provided compounds are useful in modulating proteosome function. The invention provides methods for treating a subject with ALS or other neurodegenerative disease including the step of administering to the subject a therapeutically effective amount of an inventive compound or a pharmaceutical composition thereof. In certain embodiments, the subject is a mammal.

In one aspect, the present invention provides compounds of the formula:

or a pharmaceutically acceptable salt thereof, wherein: p is 1-2;

designates a single or double bond, wherein one

is a single bond and one

is a double bond;

-   each R¹ is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R,     —N(R)₂, —CN, —NO₂—NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR,     —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R,     —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, or an optionally substituted 3-8     membered saturated, partially unsaturated, or aryl monocyclic ring     having 0-4 heteroatoms independently selected from nitrogen, oxygen,     or sulfur, or an optionally substituted 8-10 membered saturated,     partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms     independently selected from nitrogen, oxygen, or sulfur; or     -   two R¹ groups are taken together to form

-   -    wherein:         -   X is N or C;         -   each R⁵ is independently —R, —OR, —SR, —S(O)R, —SO₂R,             —OSO₂R, —N(R)₂, —CN, —NO₂—NRC(O)R, —NRC(O)(CO)R,             —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR,             —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂,             or a 3-8 membered saturated, partially unsaturated, or aryl             monocyclic ring having 0-4 heteroatoms independently             selected from nitrogen, oxygen, or sulfur, or an 8-10             membered saturated, partially unsaturated, or aryl bicyclic             ring having 0-4 heteroatoms independently selected from             nitrogen, oxygen, or sulfur, wherein R⁵ is optionally             substituted with 1-5 R groups;

-   each R is independently hydrogen, halogen, optionally substituted     C₁₋₂₀ aliphatic, optionally substituted C₁₋₂₀ heteroaliphatic,     optionally substituted phenyl, or optionally substituted arylalkyl,     or two R on the same nitrogen are taken together to form a 5-6     membered saturated, partially saturated, or aryl ring having 1-3     heteroatoms independently selected from nitrogen, oxygen, and     sulfur, or two R on the same carbon or on adjacent carbons are     optionally taken together to form a 3-6 membered saturated     cycloalkyl or fused monocyclic ring containing 0-2 heteroatoms     independently selected from nitrogen, oxygen, and sulfur;

-   n is 0-1;

-   each R² and R³ are independently —R, —OR, —SR, —S(O)R, —SO₂R,     —OSO₂R, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂,     a suitable amino protecting group, or an optionally substituted 3-8     membered saturated, partially unsaturated, or aryl monocyclic ring     having 0-4 heteroatoms independently selected from nitrogen, oxygen,     or sulfur, or an optionally substituted 8-10 membered saturated,     partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms     independently selected from nitrogen, oxygen, or sulfur;

-   R⁰ is R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, N(R)₂, —NRC(O)R,     —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R,     —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂,     —OC(O)N(R)₂, or

-    wherein:     -   L is a valence bond or a bivalent saturated or partially         unsaturated C₁₋₁₀ hydrocarbon chain, wherein 1-4 methylene units         of L are optionally and independently replaced by —O—, —S—,         —C(O)—, —OC(O)—, —C(O)O—, —OC(O)O—, —S(O)—, —S(O)₂—, —OSO₂O—,         —N(R)C(O)—, —C(O)NR—, —N(R)C(O)O—, —OC(O)NR—, —N(R)C(O)NR—,         —N(R⁶)—, or -Cy-, and wherein L is optionally substituted with         1-4 R groups; wherein:         -   each -Cy- is independently a bivalent optionally substituted             saturated, partially unsaturated, or aromatic monocyclic or             bicyclic ring selected from a 6-10 membered arylene, a 5-10             membered heteroarylene having 1-4 heteroatoms independently             selected from oxygen, nitrogen, or sulfur, a 3-8 membered             carbocyclylene, or a 3-10 membered heterocyclylene having             1-4 heteroatoms independently selected from oxygen,             nitrogen, or sulfur;         -   R⁶ is —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —C(O)R, —C(O)OR,             —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, a suitable amino             protecting group, or an optionally substituted 3-8 membered             saturated, partially unsaturated, or aryl monocyclic ring             having 0-4 heteroatoms independently selected from nitrogen,             oxygen, or sulfur, or an optionally substituted 8-10             membered saturated, partially unsaturated, or aryl bicyclic             ring having 0-4 heteroatoms independently selected from             nitrogen, oxygen, or sulfur;     -   Ring A is a 3-8 membered saturated, partially unsaturated, or         aryl monocyclic ring optionally containing 0-4 heteroatoms         independently selected from nitrogen, oxygen, or sulfur, or an         8-10 membered saturated, partially unsaturated, or aryl bicyclic         ring optionally containing 0-4 heteroatoms independently         selected from nitrogen, oxygen, or sulfur, and wherein Ring A is         optionally substituted with m occurrences of R⁴;         -   m is 0-5; and     -   each R⁴ is independently —R, —OR, —SR, —CN, —S(O)R, —SO₂R,         —OSO₂R, —N(R)₂, —NO₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂,         —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR,         —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, or a 3-8 membered         saturated, partially unsaturated, or aryl monocyclic ring         optionally containing 0-4 heteroatoms independently selected         from nitrogen, oxygen, or sulfur.

In certain embodiments, n is 0. In certain embodiments, n is 1.

In certain embodiments, p is 1. In certain embodiments, p is 2.

As described above and herein,

designates a single or double bond. It will be understood by one of ordinary skill in the art that when one

designates a double bond between two carbons to provide a compound of formula Ia:

then n is 1 and p is 1. Similarly, when

designates a double bond between a carbon and a nitrogen to provide a compound of formula Ib:

then n is 0 and p is 1 or 2, depending on the tautomeric form of 1b, e.g., in compounds of formula 1b wherein at least one R¹ is hydrogen, provided compounds may exist in any tautomeric form available. One such exemplary pair of tautomers is as shown below:

As defined generally above, each R¹ is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —N(R)₂, —CN, —NO₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, or an optionally substituted 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an optionally substituted 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; or

two R¹ groups are taken together to form

In some embodiments, each R¹ is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, N(R)₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, or —OC(O)N(R)₂.

In some embodiments, at least one R¹ is optionally substituted 3-8 membered saturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 3-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 5-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, at least one R¹ is an optionally substituted 3-8 membered partially unsaturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 3-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 5-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, at least one R¹ is an optionally substituted 5-6 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 5-6 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 5 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 6 membered aryl ring having 1-3 nitrogens. In some embodiments, at least one R¹ is an optionally substituted phenyl. In certain embodiments, at least one R¹ is unsubstituted phenyl.

In some embodiments, at least one R¹ is an optionally substituted 8-10 membered saturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 8-10 membered saturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 8-10 membered saturated bicyclic carbocycle.

In some embodiments, at least one R¹ is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 8-10 membered partially unsaturated carbocycle.

In some embodiments, at least one R¹ is an optionally substituted 9-10 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 9-10 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 9 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is an optionally substituted 10 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R¹ is optionally substituted naphthyl.

In some embodiments, two R¹ are taken together to form

wherein X is N or C. In certain embodiments wherein X is N, one R⁵ group is present. In certain embodiments wherein X is C, either one or two R⁵ groups may be present. In certain embodiments, two R¹ are taken together to form any one of the following formulae:

In some embodiments, each R⁵ is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —N(R)₂, —CN, —NO₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂. In some embodiments, at least one R⁵ is a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, wherein R⁵ is optionally substituted with 1-5 R groups.

As defined generally above and herein, R² is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, a suitable amino protecting group, or an optionally substituted 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an optionally substituted 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R² is —R, —OR, —SR, —N(R)₂, or a suitable amino protecting group. In certain embodiments, R² is halogen or R. In certain embodiments, R² is hydrogen, methyl, ethyl, propyl, or butyl. In certain embodiments, R² is hydrogen. In certain embodiments, R² is methyl.

In some embodiments, R² is an optionally substituted 3-8 membered saturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 3-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 5-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R² is an optionally substituted 3-8 membered partially unsaturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 3-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 5-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R² is an optionally substituted 5-6 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 5-6 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 5 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 6 membered aryl ring having 1-3 nitrogens. In some embodiments, R² is an optionally substituted phenyl. In certain embodiments, R² is unsubstituted phenyl.

In some embodiments, R² is an optionally substituted 8-10 membered saturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 8-10 membered saturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 8-10 membered saturated bicyclic carbocycle.

In some embodiments, R² is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 8-10 membered partially unsaturated carbocycle.

In some embodiments, R² is an optionally substituted 9-10 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 9-10 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 9 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is an optionally substituted 10 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R² is optionally substituted naphthyl.

Exemplary optionally substituted R² heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, pyrido[2,3-b]-1,4-oxazin-3(4H)-one, or chromanyl.

As defined generally above and herein, R³ is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, a suitable amino protecting group, or an optionally substituted 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an optionally substituted 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R³ is —R, —OR, —SR, —N(R)₂, or a suitable amino protecting group. In certain embodiments, R³ is halogen or R. In certain embodiments, R³ is hydrogen, methyl, ethyl, propyl, or butyl. In certain embodiments, R³ is hydrogen. In certain embodiments, R³ is methyl.

In some embodiments, R³ is an optionally substituted 3-8 membered saturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 3-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 5-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R³ is an optionally substituted 3-8 membered partially unsaturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 3-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 5-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R³ is an optionally substituted 5-6 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 5-6 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 5 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 6 membered aryl ring having 1-3 nitrogens. In some embodiments, R³ is an optionally substituted phenyl. In certain embodiments, R³ is unsubstituted phenyl.

In some embodiments, R³ is an optionally substituted 8-10 membered saturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 8-10 membered saturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 8-10 membered saturated bicyclic carbocycle.

In some embodiments, R³ is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 8-10 membered partially unsaturated carbocycle.

In some embodiments, R³ is an optionally substituted 9-10 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 9-10 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 9 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is an optionally substituted 10 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R³ is optionally substituted naphthyl.

Exemplary optionally substituted R³ heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, pyrido[2,3-b]-1,4-oxazin-3(4H)-one, or chromanyl.

In certain embodiments, R³ is of any one of the following formulae:

As described generally above and herein, R⁰ is —R—OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —N(R)₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, or

In some embodiments, R⁰ is R, wherein R is hydrogen, optionally substituted C₁₋₆ aliphatic, optionally substituted C₁₋₆ heteroaliphatic, or optionally substituted phenyl. In certain embodiments, R⁰ is methyl, ethyl, propyl, or butyl.

In some embodiments, R⁰ is

wherein R⁴, m, and Ring A are as defined above and L is a valence bond. In some embodiments, R⁰ is

wherein R⁴, m, and Ring A are as defined above and L is not a valence bond.

As defined generally above, L is a valence bond or a bivalent saturated or partially unsaturated C₁₋₁₀ hydrocarbon chain, wherein 1-4 methylene units of L are optionally and independently replaced by —O—, —S—, —C(O)—, —OC(O)—, —C(O)O—, —OC(O)O—, —S(O)—, —S(O)₂—, —OSO₂O—, —N(R)C(O)—, —C(O)NR—, —N(R)C(O)O—, —OC(O)NR—, —N(R)C(O)NR—, —N(R⁶)—, or -Cy-, and wherein L is optionally substituted with 1-4 R groups; wherein:

-   -   each -Cy- is independently a bivalent optionally substituted         saturated, partially unsaturated, or aromatic monocyclic or         bicyclic ring selected from a 6-10 membered arylene, a 5-10         membered heteroarylene having 1-4 heteroatoms independently         selected from oxygen, nitrogen, or sulfur, a 3-8 membered         carbocyclylene, or a 3-10 membered heterocyclylene having 1-4         heteroatoms independently selected from oxygen, nitrogen, or         sulfur;     -   R⁶ is —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —C(O)R, —C(O)OR,         —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, a suitable amino         protecting group, or an optionally substituted 3-8 membered         saturated, partially unsaturated, or aryl monocyclic ring having         0-4 heteroatoms independently selected from nitrogen, oxygen, or         sulfur, or an optionally substituted 8-10 membered saturated,         partially unsaturated, or aryl bicyclic ring having 0-4         heteroatoms independently selected from nitrogen, oxygen, or         sulfur.

In some embodiments, L a bivalent saturated or partially unsaturated C₁₋₁₀ hydrocarbon chain, wherein 1-4 methylene units of L are optionally and independently replaced by —O—, —N(R⁶)—, —S—, —C(O)—, —OC(O)—, —C(O)O—, —OC(O)O—, —S(O)—, —S(O)₂—, —OSO₂O—, —N(R)C(O)—, —C(O)NR—, —N(R)C(O)O—, —OC(O)NR—, —N(R)C(O)NR—, and wherein L is optionally substituted with 1-4 R groups. In some embodiments, L a bivalent saturated or partially unsaturated C₂₋₇ hydrocarbon chain, wherein 1-3 methylene units of L are optionally and independently replaced by —N(R⁶)—, —N(R)C(O)—, —C(O)N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —S—, —S(O)— or —SO₂—, and wherein L is optionally substituted with 1-4 R groups. In some embodiments, L is a bivalent saturated C₂₋₇ hydrocarbon chain, wherein one or more methylene units of L is replaced by —N(R⁶)—, —N(R)C(O)—, —C(O)N(R)—. In some embodiments, L is a bivalent saturated C₂₋₇ hydrocarbon chain, wherein one or more methylene units of L is replaced by —O—, —C(O)—, —OC(O)—, or —C(O)O—. In some embodiments, L is a bivalent saturated C₂₋₇ hydrocarbon chain, wherein one or more methylene units of L is replaced by —S—, —S(O)— or —SO₂—.

In certain embodiments, L is of any of the following formulae:

In certain embodiments, L is of any of the following formulae:

In certain embodiments, L is of any of the following formulae:

In some embodiments, L is a bivalent saturated C₁₋₁₀ hydrocarbon chain, wherein one or more methylene unit is independently replaced by -Cy-, and wherein one or more -Cy- is independently a bivalent optionally substituted saturated monocyclic ring. In some embodiments, one or more -Cy- is independently a bivalent optionally substituted partially unsaturated monocyclic ring. In some embodiments, one or more -Cy- is independently a bivalent optionally substituted aromatic monocyclic ring. In certain embodiments, -Cy- is optionally substituted phenylene.

In some embodiments, one or more -Cy- is independently a bivalent optionally substituted saturated bicyclic ring. In some embodiments, one or more -Cy- is independently a bivalent optionally substituted partially unsaturated bicyclic ring. In some embodiments, one or more -Cy- is independently a bivalent optionally substituted aromatic bicyclic ring. In certain embodiments, -Cy- is optionally substituted naphthylene.

In some embodiments, one or more -Cy- is independently an optionally substituted 6-10 membered arylene. In some embodiments, one or more -Cy- is independently an optionally substituted a 5-10 membered heteroarylene having 1-4 heteroatoms independently selected from oxygen, nitrogen, or sulfur. In some embodiments, one or more -Cy- is independently an optionally substituted a 5-6 membered heteroarylene having 1-4 heteroatoms independently selected from oxygen, nitrogen, or sulfur. In some embodiments, one or more -Cy- is independently an optionally substituted 5 membered heteroarylene having 1-4 heteroatoms independently selected from oxygen, nitrogen, or sulfur. In some embodiments, one or more -Cy- is independently an optionally substituted 6 membered heteroarylene having 1-4 heteroatoms independently selected from oxygen, nitrogen, or sulfur.

Exemplary optionally substituted -Cy- heteroarylene groups include thienylene, furanylene, pyrrolylene, imidazolylene, pyrazolylene, triazolylene, tetrazolylene, oxazolylene, isoxazolylene, oxadiazolylene, thiazolylene, isothiazolylene, thiadiazolylene, pyridylene, pyridazinylene, pyrimidinylene, pyrazinylene, indolizinylene, purinylene, naphthyridinylene, pteridinylene, indolylene, isoindolylene, benzothienylene, benzofuranylene, dibenzofuranylene, indazolylene, benzimidazolylene, benzthiazolylene, quinolylene, isoquinolylene, cinnolinylene, phthalazinylene, quinazolinylene, quinoxalinylene, 4H-quinolizinylene, carbazolylene, acridinylene, phenazinylene, phenothiazinylene, phenoxazinylene, tetrahydroquinolinylene, tetrahydroisoquinolinylene, pyrido[2,3-b]-1,4-oxazin-3(4H)-onylene, and chromanylene.

In certain embodiments, -Cy- is selected from the group consisting of tetrahydropyranylene, tetrahydrofuranylene, morpholinylene, thiomorpholinylene, piperidinylene, piperazinylene, pyrrolidinylene, tetrahydrothiophenylene, and tetrahydrothiopyranylene, wherein each ring is optionally substituted.

In some embodiments, one or more -Cy- is independently an optionally substituted 3-8 membered carbocyclylene. In some embodiments, one or more -Cy- is independently an optionally substituted 3-6 membered carbocyclylene. In some embodiments, one or more -Cy- is independently an optionally substituted cyclopropylene, cyclopentylene, or cyclohexylene.

In some embodiments, one or more -Cy- is independently an optionally substituted 3-10 membered heterocyclylene having 1-4 heteroatoms independently selected from oxygen, nitrogen, or sulfur. In some embodiments, one or more -Cy- is independently an optionally substituted 5-7 membered heterocyclylene having 1-3 heteroatoms independently selected from oxygen, nitrogen, or sulfur. In some embodiments, one or more -Cy- is independently an optionally substituted 3 membered heterocyclylene having 1 heteroatom independently selected from oxygen, nitrogen, or sulfur. In some embodiments, one or more -Cy- is independently an optionally substituted 5 membered heterocyclylene having 1-2 heteroatoms independently selected from oxygen, nitrogen, or sulfur. In some embodiments, one or more -Cy- is independently an optionally substituted 6 membered heterocyclylene having 1-3 heteroatoms independently selected from oxygen, nitrogen, or sulfur.

Exemplary -Cy- saturated 3-8 membered optionally substituted heterocyclenes include oxiranylene, oxetanylene, tetrahydrofuranylene, tetrahydropyranylene, oxepaneylene, aziridineylene, azetidineylene, pyrrolidinylene, piperidinylene, azepanylene, thiiranylene, thietanylene, tetrahydrothiophenylene, tetrahydrothiopyranylene, thiepanylene, dioxolanylene, oxathiolanylene, oxazolidinylene, imidazolidinylene, thiazolidinylene, dithiolanylene, dioxanylene, morpholinylene, oxathianylene, piperazinylene, thiomorpholinylene, dithianylene, dioxepanylene, oxazepanylene, oxathiepanylene, dithiepanylene, diazepanylene, dihydrofuranonylene, tetrahydropyranonylene, oxepanonylene, pyrrolidinonylene, piperidinonylene, azepanonylene, dihydrothiophenonylene, tetrahydrothiopyranonylene, thiepanonylene, oxazolidinonylene, oxazinanonylene, oxazepanonylene, dioxolanonylene, dioxanonylene, dioxepanonylene, oxathiolinonylene, oxathianonylene, oxathiepanonylene, thiazolidinonylene, thiazinanonylene, thiazepanonylene, imidazolidinonylene, tetrahydropyrimidinonylene, diazepanonylene, imidazolidinedionylene, oxazolidinedionylene, thiazolidinedionylene, dioxolanedionylene, oxathiolanedionylene, piperazinedionylene, morpholinedionylene, and thiomorpholinedionylene.

In some embodiments, R⁶ is —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, or —OC(O)N(R)₂. In some embodiments, R⁶ is a suitable amino protecting group. In certain embodiments, R⁶ is —SO₂R. In some embodiments, R⁶ is R. In some embodiments, R⁶ is optionally substituted arylalkyl.

In some embodiments, R⁶ is an optionally substituted 3-8 membered saturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 3-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 5-6 membered saturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R⁶ is an optionally substituted 3-8 membered partially unsaturated monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 3-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 5-6 membered partially unsaturated monocyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, R⁶ is an optionally substituted 5-6 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 5-6 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 5 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 6 membered aryl ring having 1-3 nitrogens. In some embodiments, R⁶ is an optionally substituted phenyl. In certain embodiments, R⁶ is unsubstituted phenyl.

In some embodiments, R⁶ is an optionally substituted 8-10 membered saturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 8-10 membered saturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 8-10 membered saturated bicyclic carbocycle.

In some embodiments, R⁶ is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 8-10 membered partially unsaturated bicyclic ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 8-10 membered partially unsaturated carbocycle.

In some embodiments, R⁶ is an optionally substituted 9-10 membered aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 9-10 membered aryl ring having 0-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 9 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is an optionally substituted 10 membered aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, R⁶ is optionally substituted naphthyl.

Exemplary optionally substituted R⁶ heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, pyrido[2,3-b]-1,4-oxazin-3(4H)-one, or chromanyl.

In certain embodiments, L is a bivalent saturated C₂₋₇ hydrocarbon chain wherein two methylene units are replaced by —N(R⁶)—, —N(R)C(O)—, —C(O)N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —S—, —S(O)— or —SO₂—. In certain embodiments, L is a bivalent saturated C₂₋₇ hydrocarbon chain wherein two methylene units are replaced by —O—, —S—, —S(O)—, or —SO₂—. In certain embodiments, L is a bivalent saturated C₂ hydrocarbon chain wherein at least one methylene unit is replaced by —N(R⁶)—, —N(R)C(O)—, —C(O)N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —S—, —S(O)— or —SO₂—. In certain embodiments, L is a bivalent saturated C₂ hydrocarbon chain wherein at least one methylene unit is replaced by —N(R⁶)—, —O—, —S—, —S(O)—, or —SO₂—.

In certain embodiments, L is of any of the following formulae:

As described generally above and herein, Ring A is a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring optionally containing 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring optionally containing 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and wherein Ring A is optionally substituted with m occurrences of R⁴, wherein m is 0-5. In some embodiments, m is 0, 1, 2, or 3.

In certain embodiments, Ring A is phenyl substituted with 1-5 R⁴ groups. In certain embodiments, Ring A is unsubstituted phenyl.

In certain embodiments, Ring A is naphthyl substituted with 1-5 R⁴ groups. In certain embodiments, Ring A is unsubstituted naphthyl.

In some embodiments, Ring A is a 5-6 membered monocyclic saturated, partially unsaturated or aromatic heterocyclic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and optionally substituted with 1-5 R⁴ groups. In some embodiments, Ring A is a 5 membered monocyclic heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and optionally substituted with 1-2 R⁴ groups. In other embodiments, Ring A is a 6 membered monocyclic heteroaryl ring having 1-2 nitrogens independently selected from nitrogen, oxygen, or sulfur, and optionally substituted with 1-2 R⁴ groups.

In certain embodiments, Ring A is an 8-10 membered bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and optionally substituted with 1-5 R⁴ groups. In some embodiments, Ring A is an 8 membered bicyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and optionally substituted with 1-3 R⁴ groups. In some embodiments, Ring A is a 9 membered bicyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and optionally substituted with 1-3 R⁴ groups. In some embodiments, Ring A is a 10 membered bicyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and optionally substituted with 1-3 R⁴ groups. In some embodiments, Ring A is an 8-10 membered bicyclic ring comprised of 0-2 aromatic rings and optionally substituted with 1-5 R⁴ groups.

Exemplary Ring A heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, pyrido[2,3-b]-1,4-oxazin-3(4H)-one, or chromanyl, wherein Ring A is optionally substituted with 1-5 R⁴ groups.

As described generally above and herein, each R⁴ is independently —R, —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —N(R)₂, —CN, —NO₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, —OC(O)N(R)₂, or a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring optionally containing 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, at least one R⁴ is independently —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, N(R)₂, —NO₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, or —OC(O)N(R)₂. In certain embodiments, m is 1 and R⁴ is —OR. In certain embodiments, m is 1 and R⁴ is —OMe. In certain embodiments, m is 1 and R⁴ is —NO₂. In certain embodiments, m is 1 and R⁴ is —NR₂. In certain embodiments, m is 1 and R⁴ is —NMe₂.

In some embodiments, at least one R⁴ is independently a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring optionally containing 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, at least one R⁴ is independently a 3-6 membered saturated monocyclic ring optionally containing 0-1 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, at least one R⁴ is independently a 3 membered saturated monocyclic ring optionally containing 0-1 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In certain embodiments, at least one R⁴ is cyclopropyl. In certain embodiments, two R⁴ are cyclopropyl.

In certain embodiments, at least one R⁴ is optionally substituted phenyl. In certain embodiments, at least one R⁴ is unsubstituted phenyl. In some embodiments, at least one R⁴ is independently a 5-6 membered aryl monocyclic ring containing 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In certain embodiments, R⁴ is of any of the following formulae:

In some embodiments, each R⁴ is R, wherein R is hydrogen, halogen, or optionally substituted C₁₋₂₀ aliphatic. In certain embodiments, each R⁴ is independently C₁₋₆ aliphatic. In certain embodiments, each R⁴ is independently selected from the group consisting of methyl, ethyl, propyl, or butyl. In certain embodiments, m is 1 and R⁴ is methyl, ethyl, propyl, or butyl. In certain embodiments, m is 1 and R⁴ is C₁₄ aliphatic. In some embodiments, m is 2 and each R⁴ is methyl. In some embodiments, m is 2 and each R⁴ is —CF₃.

In certain embodiments, each R⁴ is independently selected from the group consisting of fluorine, chlorine, bromine, and iodine. In certain embodiments, m is 1 and R⁴ is fluorine. In certain embodiments, m is 1 and R⁴ is chlorine. In certain embodiments, m is 1 and R⁴ is bromine. In certain embodiments, m is 2 and each R⁴ is fluorine. In certain embodiments, m is 2 and each R⁴ is chlorine. In certain embodiments, m is 2 and each R⁴ is bromine. In certain embodiments, m is 2, wherein one R⁴ is fluorine and one R⁴ is chlorine. In certain embodiments, m is 3 and each R⁴ is independently methyl or chlorine.

In certain embodiments, Ring A is of any one of the formulae:

wherein R⁴ is as defined above and herein.

In certain embodiments, Ring A is of any one of the formulae:

In certain embodiments, Ring A is of either one of the formulae:

In certain embodiments, Ring A is of the formula:

In certain embodiments, Ring A is of any one of the formulae:

wherein R⁴ is as defined above and herein.

In certain embodiments, Ring A is of the formula:

In certain embodiments, Ring A is of any one of the formulae:

wherein R⁴ is as defined above and herein.

In certain embodiments, Ring A is of either of the formulae:

In certain embodiments, Ring A is of any one of the formulae:

wherein R⁴ is as defined above and herein.

In certain embodiments, Ring A of the formula:

wherein R⁴ is as defined above and herein.

In some embodiments, a provided compound is of either of the formulae:

wherein R¹, R², R³, R⁴, L, m, and Ring A are as defined and described above and herein.

In some embodiments, a provided compound is of either of the formulae:

wherein R¹, R², R³, R⁴, L and m are as defined and described above and herein. In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), m is 1, 2, or 3. In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), m is 1 and R⁴ is meta to L. In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), m is 2 and each R⁴ is meta to L.

In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), L is not a bivalent saturated C₂ hydrocarbon chain wherein one methylene unit is replaced with —S(O)—. In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), L is a bivalent saturated C₂ hydrocarbon chain wherein one methylene unit is replaced with —S—, —O—, or —SO₂—.

In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), at least one of R¹, R², or R³ is hydrogen. In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), at least two of R¹, R², and/or R³ are hydrogen. In certain embodiments, wherein compounds are of formula 1a(i-a) or 1b(i-a), R¹, R², and R³ are all hydrogen.

In certain embodiments, a provided compound is of the formula:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In certain embodiments, a provided compound is of the formula:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In certain embodiments, a provided compound is of the formula:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In certain embodiments, a provided compound is of the formula:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of the formula:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of the formula:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of the formula:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein. In certain embodiments, R₄ is halogen or C₁-C₆ alkyl.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of the formula:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of the formula:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

In certain embodiments, a provided compound is the formula:

wherein R¹, R², R³, R⁴, R⁶ and m are as defined and described above and herein.

In certain embodiments, a provided compound is the formula:

wherein R, R¹, R², R³, R⁴, and m are as defined and described above and herein.

In certain embodiments, a provided compound is the formula:

wherein R, R¹, R², R³, R⁴, and m are as defined and described above and herein.

In certain embodiments, a provided compound is the formula:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, R⁴, R⁶ and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R, R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R, R¹, R², R³, R⁴, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, R⁴, and m are as defined and described above and herein.

In certain embodiments, a provided compound is of the formula:

wherein R¹, R², R³, R⁴ and R⁶ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R¹, R², R³, and R⁴ are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of any one of the formulae:

In some embodiments, a provided compound is of either of the formulae:

wherein R³, R⁴, R⁵, m, L, and Ring A are as defined and described above and herein.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein each R⁵ is independently —R. In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein each R⁵ is independently —OR, —SR, —S(O)R, —SO₂R, —OSO₂R, —N(R)₂, —CN, —NO₂, —NRC(O)R, —NRC(O)(CO)R, —NRC(O)N(R)₂, —NRC(O)OR, —N(R)S(O)R, —N(R)SO₂R, —N(R)SO₂OR, —C(O)R, —C(O)OR, —OC(O)R, —OC(O)OR, —C(O)N(R)₂, or —OC(O)N(R)₂. In certain embodiments, R⁵ is —NMe₂.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein at least one R₅ is a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, wherein R⁵ is optionally substituted with 1-5 R groups. In certain embodiments, at least one R₅ is a 5-6 membered aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, wherein R⁵ is optionally substituted with 1-5 R groups. In certain embodiments, at least one R⁵ is phenyl optionally substituted with 1-5 R groups.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein at least one R⁵ is a 5-6 membered heteroaryl monocyclic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and wherein R⁵ is optionally substituted with 1-5 R groups.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ is an 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, wherein R⁵ is optionally substituted with 1-5 R groups.

Exemplary R⁵ heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, pyrido[2,3-b]-1,4-oxazin-3(4H)-one, or chromanyl, wherein R⁵ is optionally substituted with 1-5 R groups.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ is of the formula:

wherein R is as defined and described above and herein.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ is of any of the formulae:

wherein R is as defined and described above and herein.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ is of any of the formulae:

wherein R is as defined and described above and herein.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ is of any of the formulae:

wherein R is as defined and described above and herein.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ is of any of the formulae:

wherein R is as defined and described above and herein.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ of the formula:

wherein R is as defined and described above and herein.

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ of any of the formulae:

In certain embodiments, a provided compound is of the formula:

In certain embodiments, a provided compound is of formula 1b(i-b) or 1b(i-c) above, wherein R⁵ of any of the formulae:

wherein R, R³, R⁴, L, and X are as defined and described above and herein.

In certain embodiments, a provided compound is of the formula:

wherein R, R³, R⁴, L, and X are as defined and described above and herein.

In certain embodiments, a provided compound is of the formula:

wherein R, R³, R⁴, L, and X are as defined and described above and herein.

In certain embodiments, a provided compound is of the formula:

wherein R, R³, R⁴, L, X, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein L and X are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

In certain embodiments, a provided compound is of the formula:

In certain embodiments, a provided compound is of the formula:

In certain embodiments, a provided compound is of the formula:

In certain embodiments, a provided compound is of the formula:

In certain embodiments, a provided compound is of the formula:

wherein R, R³, R⁴, L, and m are as defined and described above and herein.

In some embodiments, a provided compound is of any one of the formulae:

wherein R³ and R⁴ are as defined and described above and herein, and wherein L is selected from the group consisting of —CH₂O—, —CH₂S—, —CH₂S(O)—, or —CH₂SO₂—.

In some embodiments, a provided compound is of any one of the formulae:

wherein L is selected from the group consisting of —CH₂O—, —CH₂S—, —CH₂S(O)—, or —CH₂SO₂—.

In certain embodiments, a provided compound is of the formula:

In some embodiments, a provided compound is of the formula:

wherein R, R³, R⁴, and m are as defined and described above and herein, and wherein L is selected from the group consisting of —CH₂O—, —CH₂S—, —CH₂S(O)—, or —CH₂SO₂—.

Exemplary compounds of the present invention having an EC₅₀ of <20 μM in assays for protection of mutant SOD1-induced cytotoxicity are as shown below in Table 1:

TABLE 1

Methods of Treating Amyotrophic Lateral Sclerosis (ALS)

The present invention provides methods of treating ALS comprising administering a therapeutically effective amount of a provided compound or analog thereof, or pharmaceutical composition thereof, to a subject with ALS. The inventive pyrazolone may be administered to a subject in need thereof using any method of administration known in the medical arts. In certain embodiments, treatment may be administered orally or parenterally. In some embodiments, treatment is administered once a day. In some embodiments, the compound is administered two, three, four, or five times a day. In some embodiments, the compound is administered every other day. In some embodiments, the compound is administered every two days. In some embodiments, the compound is administered every three days. In some embodiments, the compound is administered every four days. In some embodiments, the compound is administered every five days. In some embodiments, the compound is administered every six days. In some embodiments, the compound is administered once a week. In some embodiments, the compound is administered at intervals as instructed by a physician for the duration of the life of the patient being treated. In certain embodiments, treatment is administered as many times a day as necessary to provide a therapeutically effective amount of a provided compound to treat a subject with ALS. In some embodiments, the subject with ALS is a mammal. In some embodiments, the subject with ALS is a rodent, such as a rat or mouse, for example, a mouse model of ALS. In certain embodiments, the subject with ALS is a human.

The efficacy of the inventive treatment may be evaluated and followed using any method known in the medical arts. The treatment of ALS may be evaluated, for example, by physical examination, laboratory testing, imaging studies, electrophysiological studies, etc.

Method of Inhibiting or Reversing Abnormal Protein Aggregation

The present invention provides a method of inhibiting or reversing abnormal protein aggregation comprising contacting in vitro or in vivo a compound of the instant invention with a cell in a therapeutically effective amount to inhibit or reverse abnormal protein aggregation. In certain embodiments, inhibition of abnormal protein aggregation occurs in vivo in a subject with ALS or another neurodegenerative disease characterized by aberrant protein aggregation (e.g., Huntington's disease, prion disease, or Alzheimer's disease). In some embodiments, the subject is a mammal. In some embodiments, the subject is a mouse or rat. In some embodiments, the subject is a human.

In certain embodiments, contact occurs in vitro, and the cell is derived from a mammalian cell line. In certain embodiments, contact occurs in vitro, and the cell is derived from a PC12 cell line. In certain embodiments, PC12 cells may additionally contain a detectable moiety to measure the extent of inhibition of aggregation. In certain embodiments, a detectable moiety is associated with a protein (e.g., SOD1). In certain embodiments, the detectable moiety is a flourescent moiety (e.g., a YFP tag). In some embodiments, the detectable moiety is a phosphorescent moiety, a radiolabel, or any other detectable moiety known in the art, and may be detected using any of the methods known in the art. In some embodiments, the detectable moiety may be detected using a high content microscopy system to allow for high-throughput screening. In certain embodiments, the detectable moiety allows for the measurement of cell viability.

Assays for the Identification of Compounds that Protect Against Protein Aggregate-Induced Cytotoxicity

The present invention also provides assays for the identification of compounds that protect against protein aggregate-induced cytotoxicity. In certain embodiments, the assays are cell protection assays that are used to identify compounds that protect cells from the cytotoxic effects of aberrant protein aggregation. In some embodiments, the assays are protein aggregation inhibition assays that are used to identify compounds that inhibit protein aggregation in a cell or in vitro. In some embodiments, the inventive assay may screen at least 1,000, 5,000, 10,000, 20,000, 30,000, 40,000, or 50,000 compounds in parallel.

Cytotoxicity Protection Assays

Compounds which protect against protein aggregate-induced cytotoxicity can be identified using methods according to the present invention. In some embodiments, the present invention provides a method of identifying compounds that protect against protein aggregate-induced cytotoxicity comprising contacting a cell expressing SOD1 or another protein susceptible to aggregation with a test compound, incubating the cell with the test compound under suitable conditions for an amount of time sufficient to observe a protective effect against protein aggregate-induced cytotoxicity, and then measuring viability in the cells treated with the test compound. In some embodiments, the extent of protein aggregation-induced cytotoxicity is measured by determining the level of a detectable moiety (e.g., a fluorescent moiety) in the cell.

In certain embodiments, the expressed protein is a mutant SOD1 protein. In some embodiments, the expressed protein is an SOD1 protein associated with a detectable moiety. In certain embodiments, the expressed protein is a fluoresently tagged mutant SOD1 protein, and the flourescent moiety is a YFP tag. In some embodiments, the detectable moiety is a phosphorescent moiety, epitope, or radiolabel. In some embodiments, the detectable moiety is any suitable detectable moiety known to those or ordinary skill in the art and may be detected using any method known in the art. In some embodiments, the detectable moiety is a fluorescent tag (e.g., a YFP tag) that can be detected with a high content microscopy system. In some embodiments, the high content microscopy system detects cell viability and facilitates high-throughput screening of a plurality of compounds.

Cells may be pre-treated with an agent that modulates the expression of a protein of interest (e.g., SOD1) in the assay. The agent may, for instance, induce the expression of a gene responsible for the protein of interest (e.g., doxycycline-inducible promoter). In some embodiments, cells may also be treated with an agent that modulates proteasome activity. In certain embodiments, the agent may be a proteasome inhibitor (e.g., MG132). In some embodiments, cell viability of cells pre-treated with an agent described herein is measured using methods described above.

In certain embodiments, the time of incubation of a cell with a test compound ranges from approximately 1 minute to approximately 1 week. In some embodiments, the time of incubation ranges from approximately 5 minutes to approximately 1 week. In some embodiments, the time of incubation ranges from approximately 30 minutes to approximately 2 days. In some embodiments, the time of incubation ranges from approximately 30 minutes to approximately 1 day. In some embodiments, the time of incubation ranges from approximately 1 hour to approximately 1 day. In some embodiments, the time of incubation ranges from approximately 1 hour to approximately 18 hours. In some embodiments, the time of incubation ranges from approximately 1 hour to approximately 12 hours. In some embodiments, the time of incubation ranges from approximately 1 hour to approximately 6 hours. In some embodiments, the time of incubation ranges from approximately 1 hour to approximately 3 hours. In some embodiments, the time of incubation is approximately 6 hours. In some embodiments, the time of incubation is approximately 12 hours. In some embodiments, the time of incubation is approximately 18 hours. In some embodiments, the time of incubation is approximately 24 hours.

In certain embodiments, the temperature during incubation of a cell with a test compound ranges from approximately 20° C. to approximately 45° C. In certain embodiments, the temperature ranges from approximately 20° C. to approximately 40° C. In certain embodiments, the temperature ranges from approximately 25° C. to approximately 40° C. In certain embodiments, the temperature ranges from approximately 30° C. to approximately 40° C. In certain embodiments, the temperature is approximately 30° C. In certain embodiments, the temperature is approximately 37° C.

Compounds that are active in the above-mentioned assay could theoretically protect against abnormal protein aggregate-induced cytotoxicity through a number of biological mechanisms. The present invention additionally provides methods to screen for compounds that protect against abnormal protein-aggregate induced cytotoxicity wherein the protein aggregation is inhibited in a non-specific manner.

Compounds which inhibit aberrant protein aggregation can be identified using methods similar to those described above in the aforementioned cytotoxicity assay. In some embodiments, the present invention provides a method of identifying compounds that inhibit aberrant protein aggregation comprising contacting a cell expressing SOD1 or other protein susceptible to aggregation with a test compound, incubating the cell with the test compound under suitable conditions, and then measuring the extent of protein aggregation in the cells treated with the test compound as compared to a control. In certain embodiments, the extent of inhibition of protein aggregation is measured by staining the protein aggregates with a detectable stain (e.g., Image-iT plasma membrane dye). In some embodiments, the detectable stain is detected using a scanning device (e.g., Cellomics Arrayscan). In certain embodiments, the protein aggregates are detected using any method of detecting protein aggregates known in the art.

Compounds identified using the above-mentioned assays may be further examined using biological assays to guide structure-activity relationship (SAR) analyses of the identified compounds. Biological assays and SAR analyses are known to those of skill in the art.

Method of Protecting Cells from the Cytotoxic Effects of Aggregated SOD1

The present invention provides a method of protecting cells against the cytotoxic effects of aggregated SOD1 protein comprising contacting in vitro or in vivo a compound of the invention with a cell in a therapeutically effective amount to protect the cell from the effects of aggregated SOD1. In certain embodiments, protection of a cell occurs in vivo in a subject with ALS. In some embodiments, the subject is a mammal. In some embodiments, the subject is a mouse or rat. In some embodiments, the subject is a human.

In other instances, protection of a cell from the cytotoxic effect of aggregated SOD1 occurs in vitro. In certain embodiments, protection occurs in vitro in a cell culture. In some embodiments, compounds of the invention are contacted with a cell line in vitro and the cell line is a mammalian cell line. In certain embodiments, the cell line is the PC12 cell line.

In some embodiments, cells are associate with a detectable moiety such as those described above. In some embodiments, cells contain a protein labeled with a detectable moiety. In certain embodiments, the protein labeled with a detectable moiety is SOD1 and the detectable moiety is a fluoresent moiety. In certain embodiments, the flourescent moiety (e.g., a YFP tag) that may be detected using a high content microscopy system to allow for high-throughput screening. In some embodiments, the detectable moiety is a phosphorescent moiety, an epitope, radiolabel, or any other detectable moiety known in the art, and may be detected using any of the methods known in the art. In certain embodiments, the detectable moiety allows for the measurement of cell viability.

Method of Measuring Changes in Ubiquitin Proteasome Activity

The present invention provides a method of measuring changes in ubiquitin proteasome activity comprising contacting in vitro or in vivo a compound of the instant invention with a cell in a therapeutically effective amount to effect a change in ubiquitin proteasome activity. In certain embodiments, modulation of proteasome activity with an inventive compound occurs in vivo in a subject with ALS. In some embodiments, the subject is a mammal. In some embodiments, the subject is a mouse or rat. In some embodiments, the subject is a human.

In certain embodiments, contact occurs in vitro by contacting a test compound with a cell, incubating the test compound with the cell using methods described above, and measuring the extent of inhibition of protein aggregation in the cell. In certain embodiments, the cell is derived from a mammalian cell line. In some embodiments, the cell is derived from a PC12 cell line or a HeLa cell line. In certain embodiments, the cells contain a detectable moiety to measure the extent to which proteasome activity is inhibited. In some embodiments, cells contain a protein labeled with a detectable moiety. In certain embodiments, the protein is SOD1 and the detectable moiety is a fluoresent moiety. In certain embodiments, the detectable moiety is a flourescent moiety (e.g., a Ubi-YFP tag). In some embodiments, the detectable moiety is a Ubi-YFP tag, which is detectable by fluorescence microscopy. In some embodiments, the detectable moiety is a phosphorescent moiety, an epitope, a radiolabel, or any other detectable moiety known in the art, and may be detected using any of the methods known in the art. In some embodiments, the detectable moiety may be detected using a high content microscopy system to allow for high-throughput screening. In certain embodiments, the detectable moiety allows for the measurement of cell viability.

Pharmaceutical Compositions

In another aspect, the present invention provides pharmaceutically compositions, which comprise a therapeutically effective amount of one or more of a provided compound, formulated together with one or more pharmaceutically acceptable carriers (additives) and/or diluents for use in treating ALS or any other diseases, disorders, or conditions. As described in detail, pharmaceutical compositions of the present invention may be specially formulated for administration in solid or liquid form, including those adapted for the following: oral administration, for example, drenches (aqueous or non-aqueous solutions or suspensions), tablets, e.g., those targeted for buccal, sublingual, and systemic absorption, boluses, powders, granules, pastes for application to the tongue; parenteral administration, for example, by subcutaneous, intramuscular, intravenous or epidural injection as, for example, a sterile solution or suspension, or sustained-release formulation; topical application, for example, as a cream, ointment, or a controlled-release patch or spray applied to the skin, lungs, or oral cavity; intravaginally or intrarectally, for example, as a pessary, cream or foam; sublingually; ocularly; transdermally; or nasally, pulmonary and to other mucosal surfaces.

Pharmaceutically acceptable salts of provided compounds include conventional nontoxic salts or quaternary ammonium salts of a compound, e.g., from nontoxic organic or inorganic acids. For example, such conventional nontoxic salts include those derived from inorganic acids such as hydrochloride, hydrobromic, sulfuric, sulfamic, phosphoric, nitric, and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, palmitic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicyclic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isothionic, and the like.

In other cases, provided compounds may contain one or more acidic functional groups and, thus, are capable of forming pharmaceutically-acceptable salts with pharmaceutically-acceptable bases. These salts can likewise be prepared in situ in the administration vehicle or the dosage form manufacturing process, or by separately reacting the purified compound in its free acid form with a suitable base, such as the hydroxide, carbonate or bicarbonate of a pharmaceutically-acceptable metal cation, with ammonia, or with a pharmaceutically-acceptable organic primary, secondary or tertiary amine. Representative alkali or alkaline earth salts include the lithium, sodium, potassium, calcium, magnesium, and aluminum salts and the like. Representative organic amines useful for the formation of base addition salts include ethylamine, diethylamine, ethylenediamine, ethanolamine, diethanolamine, piperazine and the like. See, for example, Berge et al., supra.

Wetting agents, emulsifiers and lubricants, such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, release agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the compositions.

Examples of pharmaceutically acceptable antioxidants include: water soluble antioxidants, such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite and the like; oil-soluble antioxidants, such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, alpha-tocopherol, and the like; and metal chelating agents, such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, and the like.

Formulations of the present invention include those suitable for oral, nasal, topical (including buccal and sublingual), rectal, vaginal and/or parenteral administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. The amount of active ingredient which can be combined with a carrier material to produce a single dosage form will vary depending upon the host being treated, and the particular mode of administration. The amount of active ingredient that can be combined with a carrier material to produce a single dosage form will generally be that amount of the compound which produces a therapeutic effect. Generally, this amount will range from about 1% to about 99% of active ingredient, preferably from about 5% to about 70%, most preferably from about 10% to about 30%.

In certain embodiments, a formulation of the present invention comprises an excipient selected from the group consisting of cyclodextrins, liposomes, micelle forming agents, e.g., bile acids, and polymeric carriers, e.g., polyesters and polyanhydrides; and a compound of the present invention. In certain embodiments, an aforementioned formulation renders orally bioavailable a compound of the present invention.

Methods of preparing formulations or compositions comprising provided compounds include a step of bringing into association a compound of the present invention with the carrier and, optionally, one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association a compound of the present invention with liquid carriers, or finely divided solid carriers, or both, and then, if necessary, shaping the product.

Formulations of the invention suitable for oral administration may be in the form of capsules, cachets, pills, tablets, lozenges (using a flavored basis, usually sucrose and acacia or tragacanth), powders, granules, or as a solution or a suspension in an aqueous or non-aqueous liquid, or as an oil-in-water or water-in-oil liquid emulsion, or as an elixir or syrup, or as pastilles (using an inert base, such as gelatin and glycerin, or sucrose and acacia) and/or as mouth washes and the like, each containing a predetermined amount of a compound of the present invention as an active ingredient. A compound of the present invention may also be administered as a bolus, electuary or paste.

In solid dosage forms of the invention for oral administration (capsules, tablets, pills, dragees, powders, granules and the like), the active ingredient is mixed with one or more pharmaceutically-acceptable carriers, such as sodium citrate or dicalcium phosphate, and/or any of the following: fillers or extenders, such as starches, lactose, sucrose, glucose, mannitol, and/or silicic acid; binders, such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinyl pyrrolidone, sucrose and/or acacia; humectants, such as glycerol; disintegrating agents, such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate; solution retarding agents, such as paraffin; absorption accelerators, such as quaternary ammonium compounds; wetting agents, such as, for example, cetyl alcohol, glycerol monostearate, and non-ionic surfactants; absorbents, such as kaolin and bentonite clay; lubricants, such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof; and coloring agents. In the case of capsules, tablets and pills, the pharmaceutical compositions may also comprise buffering agents. Solid compositions of a similar type may also be employed as fillers in soft and hard-shelled gelatin capsules using such excipients as lactose or milk sugars, as well as high molecular weight polyethylene glycols and the like.

Tablets may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared using binder (for example, gelatin or hydroxypropylmethyl cellulose), lubricant, inert diluent, preservative, disintegrant (for example, sodium starch glycolate or cross-linked sodium carboxymethyl cellulose), surface-active or dispersing agent. Molded tablets may be made in a suitable machine in which a mixture of the powdered compound is moistened with an inert liquid diluent.

Tablets, and other solid dosage forms of pharmaceutical compositions of the present invention, such as dragees, capsules, pills and granules, may optionally be scored or prepared with coatings and shells, such as enteric coatings and other coatings well known in the pharmaceutical-formulating art. They may also be formulated so as to provide slow or controlled release of the active ingredient therein using, for example, hydroxypropylmethyl cellulose in varying proportions to provide the desired release profile, other polymer matrices, liposomes and/or microspheres. They may be formulated for rapid release, e.g., freeze-dried. They may be sterilized by, for example, filtration through a bacteria-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions that can be dissolved in sterile water, or some other sterile injectable medium immediately before use. These compositions may also optionally contain opacifying agents and may be of a composition that they release the active ingredient(s) only, or preferentially, in a certain portion of the gastrointestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes. The active ingredient can also be in micro-encapsulated form, if appropriate, with one or more of the above-described excipients.

Liquid dosage forms for oral administration of compounds of the invention include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active ingredient, the liquid dosage forms may contain inert diluents commonly used in the art, such as, for example, water or other solvents, solubilizing agents and emulsifiers, such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor and sesame oils), glycerol, tetrahydrofuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof.

Besides inert diluents, oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, coloring, perfuming and preservative agents.

Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth, and mixtures thereof.

Formulations of pharmaceutical compositions of the invention for rectal or vaginal administration may be presented as a suppository, which may be prepared by mixing one or more compounds of the invention with one or more suitable nonirritating excipients or carriers comprising, for example, cocoa butter, polyethylene glycol, a suppository wax or a salicylate, and which is solid at room temperature, but liquid at body temperature and, therefore, will melt in the rectum or vaginal cavity and release the active compound.

Dosage forms for topical or transdermal administration of a compound of this invention include powders, sprays, ointments, pastes, creams, lotions, gels, solutions, patches and inhalants. The active compound may be mixed under sterile conditions with a pharmaceutically-acceptable carrier, and with any preservatives, buffers, or propellants which may be required.

The ointments, pastes, creams and gels may contain, in addition to an active compound of this invention, excipients, such as animal and vegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicic acid, talc and zinc oxide, or mixtures thereof.

Powders and sprays can contain, in addition to a compound of this invention, excipients such as lactose, talc, silicic acid, aluminum hydroxide, calcium silicates and polyamide powder, or mixtures of these substances. Sprays can additionally contain customary propellants, such as chlorofluorohydrocarbons and volatile unsubstituted hydrocarbons, such as butane and propane.

Transdermal patches have the added advantage of providing controlled delivery of a compound of the present invention to the body. Dissolving or dispersing the compound in the proper medium can make such dosage forms. Absorption enhancers can also be used to increase the flux of the compound across the skin. Either providing a rate controlling membrane or dispersing the compound in a polymer matrix or gel can control the rate of such flux.

Ophthalmic formulations, eye ointments, powders, solutions and the like, are also contemplated as being within the scope of this invention.

Pharmaceutical compositions of this invention suitable for parenteral administration comprise one or more compounds of the invention in combination with one or more pharmaceutically-acceptable sterile isotonic aqueous or nonaqueous solutions, dispersions, suspensions or emulsions, or sterile powders which may be reconstituted into sterile injectable solutions or dispersions just prior to use, which may contain sugars, alcohols, antioxidants, buffers, bacteriostats, solutes which render the formulation isotonic with the blood of the intended recipient or suspending or thickening agents.

Examples of suitable aqueous and nonaqueous carriers, which may be employed in the pharmaceutical compositions of the invention include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.

These compositions may also contain adjuvants such as preservatives, wetting agents, emulsifying agents and dispersing agents. Prevention of the action of microorganisms upon the subject compounds may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents, such as sugars, sodium chloride, and the like into the compositions. In addition, prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin.

In some cases, in order to prolong the effect of a drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material having poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution, which in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally-administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle.

Injectable depot forms are made by forming microencapsule matrices of the subject compounds in biodegradable polymers such as polylactide-polyglycolide. Depending on the ratio of drug to polymer, and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions, which are compatible with body tissue.

In certain embodiments, a compound or pharmaceutical preparation is administered orally. In other embodiments, the compound or pharmaceutical preparation is administered intravenously. Alternative routs of administration include sublingual, intramuscular, and transdermal administrations.

When the compounds of the present invention are administered as pharmaceuticals, to humans and animals, they can be given per se or as a pharmaceutical composition containing, for example, 0.1% to 99.5% (more preferably, 0.5% to 90%) of active ingredient in combination with a pharmaceutically acceptable carrier.

The preparations of the present invention may be given orally, parenterally, topically, or rectally. They are of course given in forms suitable for each administration route. For example, they are administered in tablets or capsule form, by injection, inhalation, eye lotion, ointment, suppository, etc. administration by injection, infusion or inhalation; topical by lotion or ointment; and rectal by suppositories. Oral administrations are preferred.

These compounds may be administered to humans and other animals for therapy by any suitable route of administration, including orally, nasally, as by, for example, a spray, rectally, intravaginally, parenterally, intracisternally and topically, as by powders, ointments or drops, including buccally and sublingually.

Regardless of the route of administration selected, the compounds of the present invention, which may be used in a suitable hydrated form, and/or the pharmaceutical compositions of the present invention, are formulated into pharmaceutically-acceptable dosage forms by conventional methods known to those of skill in the art.

Actual dosage levels of the active ingredients in the pharmaceutical compositions of this invention may be varied so as to obtain an amount of the active ingredient that is effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration, without being toxic to the patient.

The selected dosage level will depend upon a variety of factors including the activity of the particular compound of the present invention employed, or the ester, salt or amide thereof, the route of administration, the time of administration, the rate of excretion or metabolism of the particular compound being employed, the duration of the treatment, other drugs, compounds and/or materials used in combination with the particular compound employed, the age, sex, weight, condition, general health and prior medical history of the patient being treated, and like factors well known in the medical arts.

A physician or veterinarian having ordinary skill in the art can readily determine and prescribe the effective amount of the pharmaceutical composition required. For example, the physician or veterinarian could start doses of the compounds of the invention employed in the pharmaceutical composition at levels lower than that required to achieve the desired therapeutic effect and then gradually increasing the dosage until the desired effect is achieved.

In some embodiments, one or more provided compounds, or pharmaceutical compositions thereof, is provided to a synucleinopathic subject chronically. Chronic treatments include any form of repeated administration for an extended period of time, such as repeated administrations for one or more months, between a month and a year, one or more years, or longer. In many embodiments, chronic treatment involves administering one or more provided compounds, or pharmaceutical compositions thereof, repeatedly over the life of the subject. Preferred chronic treatments involve regular administrations, for example one or more times a day, one or more times a week, or one or more times a month. In general, a suitable dose such as a daily dose of one or more provided compounds, or pharmaceutical compositions thereof, will be that amount of the one or more provided compound that is the lowest dose effective to produce a therapeutic effect. Such an effective dose will generally depend upon the factors described above. Generally doses of the compounds of this invention for a patient, when used for the indicated effects, will range from about 0.0001 to about 100 mg per kg of body weight per day. Preferably, the daily dosage will range from 0.001 to 50 mg of compound per kg of body weight, and even more preferably from 0.01 to 10 mg of compound per kg of body weight. However, lower or higher doses can be used. In some embodiments, the dose administered to a subject may be modified as the physiology of the subject changes due to age, disease progression, weight, or other factors.

If desired, the effective daily dose of one or more provided compounds may be administered as two, three, four, five, six, or more sub-doses administered separately at appropriate intervals throughout the day, optionally, in unit dosage forms.

While it is possible for a provided compound to be administered alone, it is preferable to administer a provided compound as a pharmaceutical formulation (composition) as described above.

Provided compounds may be formulated for administration in any convenient way for use in human or veterinary medicine, by analogy with other pharmaceuticals.

According to the invention, provided compounds for treating neurological conditions or diseases can be formulated or administered using methods that help the compounds cross the blood-brain barrier (BBB). The vertebrate brain (and CNS) has a unique capillary system unlike that in any other organ in the body. The unique capillary system has morphologic characteristics which make up the blood-brain barrier (BBB). The blood-brain barrier acts as a system-wide cellular membrane that separates the brain interstitial space from the blood.

The unique morphologic characteristics of the brain capillaries that make up the BBB are: (a) epithelial-like high resistance tight junctions which literally cement all endothelia of brain capillaries together, and (b) scanty pinocytosis or transendothelial channels, which are abundant in endothelia of peripheral organs. Due to the unique characteristics of the blood-brain barrier, hydrophilic drugs and peptides that readily gain access to other tissues in the body are barred from entry into the brain or their rates of entry and/or accumulation in the brain are very low.

In one aspect of the invention, provided compounds that cross the BBB are particularly useful for treating synucleinopathies. In one embodiment, provided compounds that cross the BBB are particularly useful for treating amyotrophic lateral sclerosis (ALS). Therefore it will be appreciated by a person of ordinary skill in the art that some of the compounds of the invention might readily cross the BBB. Alternatively, the compounds of the invention can be modified, for example, by the addition of various substitutuents that would make them less hydrophilic and allow them to more readily cross the BBB.

Various strategies have been developed for introducing those drugs into the brain which otherwise would not cross the blood-brain barrier. Widely used strategies involve invasive procedures where the drug is delivered directly into the brain. One such procedure is the implantation of a catheter into the ventricular system to bypass the blood-brain barrier and deliver the drug directly to the brain. These procedures have been used in the treatment of brain diseases which have a predilection for the meninges, e.g., leukemic involvement of the brain (U.S. Pat. No. 4,902,505, incorporated herein in its entirety by reference).

Although invasive procedures for the direct delivery of drugs to the brain ventricles have experienced some success, they are limited in that they may only distribute the drug to superficial areas of the brain tissues, and not to the structures deep within the brain. Further, the invasive procedures are potentially harmful to the patient.

Other approaches to circumventing the blood-brain barrier utilize pharmacologic-based procedures involving drug latentiation or the conversion of hydrophilic drugs into lipid-soluble drugs. The majority of the latentiation approaches involve blocking the hydroxyl, carboxyl and primary amine groups on the drug to make it more lipid-soluble and therefore more easily able to cross the blood-brain barrier.

Another approach to increasing the permeability of the BBB to drugs involves the intra-arterial infusion of hypertonic substances which transiently open the blood-brain barrier to allow passage of hydrophilic drugs. However, hypertonic substances are potentially toxic and may damage the blood-brain barrier.

Antibodies are another method for delivery of compositions of the invention. For example, an antibody that is reactive with a transferrin receptor present on a brain capillary endothelial cell, can be conjugated to a neuropharmaceutical agent to produce an antibody-neuropharmaceutical agent conjugate (U.S. Pat. No. 5,004,697, incorporated herein in its entirety by reference). The method is conducted under conditions whereby the antibody binds to the transferrin receptor on the brain capillary endothelial cell and the neuropharmaceutical agent is transferred across the blood brain barrier in a pharmaceutically active form. The uptake or transport of antibodies into the brain can also be greatly increased by cationizing the antibodies to form cationized antibodies having an isoelectric point of between about 8.0 to 11.0 (U.S. Pat. No. 5,527,527, incorporated herein in its entirety by reference).

A ligand-neuropharmaceutical agent fusion protein is another method useful for delivery of compositions to a host (U.S. Pat. No. 5,977,307, incorporated herein in its entirety by reference). The ligand is reactive with a brain capillary endothelial cell receptor. The method is conducted under conditions whereby the ligand binds to the receptor on a brain capillary endothelial cell and the neuropharmaceutical agent is transferred across the blood brain barrier in a pharmaceutically active form. In some embodiments, a ligand-neuropharmaceutical agent fusion protein, which has both ligand binding and neuropharmaceutical characteristics, can be produced as a contiguous protein by using genetic engineering techniques. Gene constructs can be prepared comprising DNA encoding the ligand fused to DNA encoding the protein, polypeptide or peptide to be delivered across the blood brain barrier. The ligand coding sequence and the agent coding sequence are inserted in the expression vectors in a suitable manner for proper expression of the desired fusion protein. The gene fusion is expressed as a contiguous protein molecule containing both a ligand portion and a neuropharmaceutical agent portion.

The permeability of the blood brain barrier can be increased by administering a blood brain barrier agonist, for example bradykinin (U.S. Pat. No. 5,112,596, incorporated herein in its entirety by reference), or polypeptides called receptor mediated permeabilizers (RMP) (U.S. Pat. No. 5,268,164, incorporated herein in its entirety by reference). Exogenous molecules can be administered to the host's bloodstream parenterally by subcutaneous, intravenous or intramuscular injection or by absorption through a bodily tissue, such as the digestive tract, the respiratory system or the skin. The form in which the molecule is administered (e.g., capsule, tablet, solution, emulsion) depends, at least in part, on the route by which it is administered. The administration of the exogenous molecule to the host's bloodstream and the intravenous injection of the agonist of blood-brain barrier permeability can occur simultaneously or sequentially in time. For example, a therapeutic drug can be administered orally in tablet form while the intravenous administration of an agonist of blood-brain barrier permeability is given later (e.g., between 30 minutes later and several hours later). This allows time for the drug to be absorbed in the gastrointestinal tract and taken up by the bloodstream before the agonist is given to increase the permeability of the blood-brain barrier to the drug. On the other hand, an agonist of blood-brain barrier permeability (e.g., bradykinin) can be administered before or at the same time as an intravenous injection of a drug. Thus, the term “co-administration” is used herein to mean that the agonist of blood-brain barrier and the exogenous molecule will be administered at times that will achieve significant concentrations in the blood for producing the simultaneous effects of increasing the permeability of the blood-brain barrier and allowing the maximum passage of the exogenous molecule from the blood to the cells of the central nervous system.

In other embodiments, a provided compound can be formulated as a prodrug with a fatty acid carrier (and optionally with another neuroactive drug). The prodrug is stable in the environment of both the stomach and the bloodstream and may be delivered by ingestion. The prodrug passes readily through the blood brain barrier. The prodrug preferably has a brain penetration index of at least two times the brain penetration index of the drug alone. Once in the central nervous system, the prodrug, which preferably is inactive, is hydrolyzed into the fatty acid carrier and a provided compound or analog thereof (and optionally another drug). The carrier preferably is a normal component of the central nervous system and is inactive and harmless. The compound and/or drug, once released from the fatty acid carrier, is active. Preferably, the fatty acid carrier is a partially-saturated straight chain molecule having between about 16 and 26 carbon atoms, and more preferably 20 and 24 carbon atoms. Examples of fatty acid carriers are provided in U.S. Pat. Nos. 4,939,174; 4,933,324; 5,994,932; 6,107,499; 6,258,836; and 6,407,137, the disclosures of which are incorporated herein by reference in their entirety.

Administration of agents of the present invention may be for either prophylactic or therapeutic purposes. When provided prophylactically, the agent is provided in advance of disease symptoms. The prophylactic administration of the agent serves to prevent or reduce the rate of onset of symptoms of ALS. When provided therapeutically, the agent is provided at (or shortly after) the onset of the appearance of symptoms of actual disease. In some embodiments, the therapeutic administration of the agent serves to reduce the severity and duration of the disease.

The function and advantage of these and other embodiments of the present invention will be more fully understood from the examples described below. The following examples are intended to illustrate the benefits of the present invention, but do not exemplify the full scope of the invention.

EXAMPLES Example 1. High Throughput Assays for Protection from Mutant SOD1-Induced Cytotoxicity

Cultured cells are utilized to conduct high throughput assays for compounds that protect against mutant SOD1-induced cytotoxicity. Two assays are used: first, in the cytotoxicity protection assay, compounds are screened for their ability to protect cells from the cytotoxic effects of aggregated mutant SOD1, irrespective of mechanism of drug action. Second, in the protein aggregation assay, compounds are screened for their ability to reduce aggregation of mutant SOD1. The high throughput cytotoxicity protection assay is the primary screen and compounds active in the primary screen (and their analogs) move forward into the secondary screen for protein aggregation.

Assay for Protection Against Mutant SOD1-Induced Cytotoxicity

The high throughput cytotoxicity protection assay was carried out in PC12 cells that express mutant G93A SOD1 as a YFP fusion protein from a doxycycline-inducible promoter. Several lines of evidence suggest that cytotoxicity of protein aggregates in ALS is due at least in part to inhibition of the proteasome (Bruijin et al. Annu. Rev. Neurosci. 2004, 27, 723-729; Cleveland et al. Nat. Rev. Neurosci. 2001, 2(11), 806). This idea was tested by examining the sensitivity of PC12 cells to SOD1 aggregates in the presence and absence of proteasome inhibitor MG132. PC12 cells expressing no SOD1, wild type SOD1, G85R SOD1 or G93A SOD1 were grown with or without MG132 (FIG. 1). Cells expressing no SOD1, wild type SOD1 and G85R SOD1 were relatively insensitive to MG132, with an IC₅₀ of approximately 400 nM. In contrast, cells expressing G93A SOD1 were approximately 5-fold more sensitive to MG132 (IC₅₀ ˜75 nM). In these cells, protein aggregation was detected after 24 h and loss of cell viability was detected at approximately 48 h. Qualitatively similar results were obtained with the structurally distinct proteasome inhibitor bortezomib (Velcade®), suggesting that PC12 cells are indeed susceptible to proteasome inhibition and not some other effect of MG132. The ability of protein aggregates to induce cell death was examined by treating G93A SOD1-expressing cells with MG132 for 24 h, removing the MG132 by washing and assaying cell viability after another 24 h. Because the loss of cell viability was similar following MG132 removal (FIG. 1, part C), it is likely that mutant SOD1 aggregates contribute directly to cytotoxicity in PC12 cells. However, this effect is specific for G93A SOD1 suggesting that this mutant may produce higher levels of a toxic aggregated form of SOD1.

Based on these results, a high throughput screen was developed for compounds that protect against the cytotoxicity of G93A SOD1 protein aggregates using geldanamycin or radicicol as a positive control. PC12 cells expressing G93A SOD1 were treated with 100 nM MG132 with or without co-treatment with geldanamycin or radicicol. The latter compounds inhibit the chaperone HSP90 and induce expression of other chaperones. As anticipated, radicicol reduced formation of protein aggregates and increased cell viability in a dose-dependent manner (FIG. 2). Statistical analysis of the data produced a Z′ value of 0.55, which would predict good performance as a positive control in a high throughput screen (Zhang et al., J. Biomol. Screen 1999, 4(2), 67-73).

Mutant SOD1 Direct Protein Aggregation Assay.

Compounds that are active in the above assay could theoretically protect against mutant SOD1-induced cytotoxicity through a number of mechanisms, including the following: 1) compounds could nonspecifically block or reverse protein aggregation via chaperone induction, as observed for radicicol and geldanamycin; 2) compounds could block or reverse the aggregation of a specific aggregated protein form; 3) compounds could interfere with an event downstream of protein aggregation that plays a critical role in mutant SOD1-induced cytotoxicity (e.g., proteasome function); and 4) compounds could act directly on SOD1 in a manner that prevents mutant SOD1 aggregation. These possibilities were tested using an assay that directly measures protein aggregation. In addition, unlike the high throughput cytotoxicity protection assay, the protein aggregation assay is based on G85R SOD1; this broadens the scope of the screening strategy, and should eliminate compounds with highly specific activity (i.e., G93A SOD 1 limited) against protein aggregation.

In PC12 cells that express wild-type SOD1, SOD1 was diffusely localized throughout the cell (Matsumoto et al., J. Cell. Biol. 2005, 171(1), 75-85). In contrast, G85R SOD1 showed heterogeneous patterns of localization; in most cells, G85R was diffusely localized throughout the cell, but in ˜5% of the cells, G85R SOD1 was localized in large peri-nuclear aggregates. In cells treated with MG132, up to 75% of cells expressing G85R SOD1 contain such protein aggregates (FIG. 3), but no aggregation was observed in cells expressing wild-type SOD1. Cells expressing G93A mutant SOD1 showed an intermediate level of protein aggregation: none of the cells developed protein aggregates in the absence of MG132, and ˜75% of the cells had protein aggregates following treatment with MG132 (FIG. 3). Similar effects were observed in cells treated with bortezomib (Velcade®). Therefore, these effects are likely to be due to MG132-induced proteasome inhibition, and not due to an off-target effect of MG132.

The sensitivity of this assay was optimized by selecting conditions that maximize the difference between active and inactive samples. The identification of a positive control is a crucial step in assay development. Thus, PC12 cells expressing G85R or G93A mutant SOD1 were treated with MG132 to induce protein aggregation, and then co-treated with candidate chemical suppressors of protein aggregation. Two compounds with similar activity were identified in these experiments: geldanamycin and radicicol. Both compounds induce heat shock transcription factor NSF-1, which in turn induces the heat shock response (FIG. 4). Treatment with radicicol reduced the proportion of cells with aggregates from 75% to 25%, a sufficient difference to allow visual scoring for compounds with efficacy equal to or greater than radicicol.

To allow this assay to be used in a high-throughput manner, a Cellomics Arrayscan® high content microscopy system was used for screening and quantification. Initial experiments indicated that G85R SOD1 aggregates were more readily recognized by the high content microscopy system and its computer algorithm. Because the most robust high content assays measure events on a per cell basis, it was necessary to select a fluorescent stain that marks whole cells to be used with a compatible stain that marks intracellular structures. On the basis of pilot experiments with a number of vital dyes, an Image-iT conjugated wheat germ agglutinin (WGA) dye from Molecular Probes was selected and a computer algorithm for detecting WGA was developed. As shown in FIG. 5, WGA provided an excellent cellular marker that did not interfere with detection of YFP-tagged SOD1.

Initial experiments used geldanamycin and radicicol as positive controls, both of which are reproducibly active, but did not show highly statistically reliable performance when the high content microscopy system was used. Therefore, pyrazolones CMB-3350 and CMB-3319 were tested as alternate positive controls. CMB-3350 and CMB-3319 were selected because of their outstanding activity in the SOD1 cytotoxicity protection assay.

Example 2. Procedures and Protocols for High Throughput Screening

Mutant SOD1-Induced Cytotoxicity Protection Assay: Automated High Throughput Screening Protocol.

PC12 cells were maintained in Dulbecco's Modified Eagle's Medium (Invitrogen), supplemented with 10% horse serum, 0.1 μ/ml NGF (Sigma), and 0.1 μ/ml doxycycline (Sigma). Cells were incubated at 37° C. in a humidified atmosphere with 5% CO₂. The expression of SOD1 protein was induced by the withdrawal of doxycycline from the media. For screening in microwell format, cells were seeded at 15,000 cells/well in 96-well plates (Falcon-BD) using a Multidrop 384 (Thermo Lab Systems) and incubated 24 h prior to compound addition. Compounds (control and test) were added to wells using a Zymark Sciclone. MG132 was added 24 h later using the Multidrop 384. Cell viability was measured after 48 h using the fluorescent viability probe calcein-AM (Molecular Probes). Fluorescence intensity was measured using a POLARstar fluorescence plate reader (BMG). All experiments included positive control wells treated with radicicol at 700 nM and negative control wells treated with DMSO. Fluorescence data were coupled with compound structural data, then stored and analyzed using the Cambridgesoft Chemoffice Enterprise Ultra software package.

Mutant SOD1 Aggregation Assay: Automated High Content Screening Protocol.

PC12 cells were maintained in Dulbecco's Modified Eagle's Medium (Invitrogen) supplemented with 10% horse serum, plus 0.1 μ/ml NGF (Sigma) and 0.1 μg/ml doxycycline (Sigma). Cells were incubated at 37° C. in a humidified atmosphere with 5% CO₂ and are routinely subcultured using 0.05% trypsin-EDTA solution. The expression of SOD1 protein was induced by the withdrawal of doxycycline from the media. For screening in microwell format, cells were seeded at 5,000 cells/well in 96-well plates (Falcon-BD) using a Thermo Labsystems Multidrop 384. Compounds (control and test) were added to wells using a Zymark Sciclone. Test compounds were incubated with the cells for 24 h prior to the addition of MG132. CMB-3350 was used as a positive control at 5 μM, DMSO as a negative control and test compounds were applied at 512M. MG132 was then added at 1 μM final concentration and the cells were grown for an additional 24 hours. To assay protein aggregation, cell culture medium was then removed and the cells were washed once with HBSS then incubated in HBSS containing 5 μg/ml of the Image-iT WGA plasma membrane dye (Molecular Probes) for 15 min at 37° C. Cells were then washed with PBS and imaged using the Cellomics Arrayscan®.

Assay Automation.

Arrayscan images were recorded using a 20× objective and the XF93-TRITC filter set in channel 1 for the Image-iT WGA plasma membrane dye or the XF93-FITC filter set for SOD1-YFP and analyzed using Cellomics spot detector software. Software parameters were set to maximally differentiate cells from background and maximize recognition of SOD1 aggregates without recognizing background cytoplasmic staining as a spot. Data were recorded as spot count (aggregate)/object (cell).

A library was screened using the cytotoxicity protection assay as the primary screen and the protein aggregation assay as the secondary screen. The overall screen produced an average Z′ factor of 0.5 and an average Z factor of 0.6. Using 60% viability as the cutoff for activity, 195 primary actives were recovered (0.38% primary hit rate). All primary actives were retested in dose response curves yielding 68 confirmed actives (0.13% confirmed hit rate). These actives were then tested for auto-fluorescence and inhibition of protein synthesis, potential causes of artifactual positives. Confirmed primary actives were assayed in the high content protein aggregation screen and grouped into compounds that were positive or negative in the secondary screen. Cheminformatic analysis of these compounds identified 17 chemotypes of structurally-related active and inactive compounds plus 15 singleton hits. Most active compounds were also active in the secondary high content assay, two of the confirmed primary actives were not. Initial biological analysis focused on the arylsulfanyl pyrazolone lead series. The compound collection includes riluzole, which tested negative indicating that the actives tested here differ from the sole clinically approved drug for ALS.

Counterscreens.

All active compounds were tested for autofluorescence, a potential artifact in any fluorescence assay. This test only identified one compound with significant autofluorescence. This low rate of autofluorescence might be due to the use of calcein-AM to measure cell viability. Calcein-AM is a high quantum yield reagent and thus only highly fluorescent compounds produce a comparable signal. All active compounds were tested for ability to inhibit protein synthesis, as this could artificially reduce protein aggregation. Specific reduction in the cellular concentration of SOD1 was estimated using a modification of the high content assay, in which YFP fluorescence was measured with a plate reader prior to counting the number of cells per well with ArrayScan. This yielded a value for YFP fluorescence per cell, which is equivalent to SOD1 content per cell. No compounds tested active in this assay. Lastly, all active compounds were tested for nonspecific cytotoxicity in untransfected PC12 cells. The vast majority of the active compounds lacked or had extremely low non-specific cytotoxicity. One possible explanation for the low level of cytotoxicity associated with active compounds is that the primary protection screen selected specifically against such compounds.

Discovery and Preliminary SAR of Chemical Lead Series.

Results show that certain provided compounds and analogs thereof were active (ED₅₀≤20 μM) in the cytotoxicity protection assay. Compounds that were tested in the SOD1 protein aggregation assay are also indicated.

Chemical Identification and Analog Selection.

All active compounds were reordered and re-tested from dry powder to confirm activity. Confirmed active compounds were characterized by an iterative process designed to establish preliminary SAR. This process included reanalyzing the screening files to identify structurally-related but weakly active or inactive compounds and testing structurally-related compounds purchased from commercial suppliers. Over 300 chemical compounds were acquired from an extensive search of over 2 million unique available commercial compounds on the basis of a substructure and Tanimoto similarity analysis carried out using an in-house vendor chemical warehouse database system. All compounds were ≥90% pure (by LC/MS and/or ¹H NMR).

Biological Assays to Guide SAR Analysis.

The high throughput cytotoxicity protection assay and the high content protein aggregation assay only score compounds as active or inactive. Two quantitative metrics were therefore developed to evaluate compound activity for SAR development: potency (ED₅₀), which is the concentration producing half maximal cell viability, and efficacy, which is defined as the maximum viability produced by a compound at its optimum dosage. Cytotoxicity is measured by determining the concentration that reduces PC12 cell viability by 50% and is reported as the cytotoxicity IC₅₀ (FIG. 2). Compounds were also tested for nonspecific inhibition of protein synthesis, inhibition of protein aggregation (i.e., SOD1-YFP fusion) and autofluorescence (to ensure the detection method was not detecting false positives).

Summary of Biological Effects.

Most of the active compounds showed 100% efficacy as compared with the positive control, radicicol, which showed only 80% efficacy at the most efficacious dose. The most potent compounds produce ED₅₀ values between 100 nM and 2 μM in the cytotoxicity protection assay. Compounds that were active in the cytotoxicity protection assay were active in the protein aggregation assay with comparable potency (Table 2). Thus, it is reasonable to assume that these compounds reduce cytotoxicity by reducing mutant SOD1 aggregation. These compounds are generally not cytotoxic or only very weakly cytotoxic. Structure-activity relationship studies of provided compounds were conducted by comparing the activity of compounds with substitutions at N-2, C-4 and C-5 around the pyrazole ring. Compounds without substitution at N-2 (R1) or N-2 (R1) & C-4 (R3) that contain an arylsulfanyl moiety at C-5 (R2) were most potent, with ED50 values between 0.374 and 5 μM. Alkene substituted compounds at C-4, such as dimethyl amine and various substituted aromatic and heterocyclic groups, with a C-5 arylsulfanyl group are equally potent, with ED₅₀ values between 0.6 and 5 μM. All substituted alkenes were tested as mixed isomers (E and Z). Table 3 lists selected compounds in this series with an ED₅₀<μM in the cytotoxicity protection assay. The most potent active compounds (CMB-3319 & CMB-3350) are the C-5 substituted pyrazoles containing an arylsulfanyl group. CMB-3299 is similar to CMB-3319, but has a methyl substitution at C2 rather than a chlorine group on the arylsulfanyl ring system.

Mechanistic Studies on Arylsulfanyl Pyrazolones.

Mechanism of action studies have been initiated for provided compounds. provided compounds active in the cytotoxicity protection assay were initially assayed for the ability to prevent SOD1 aggregation using manual, low-throughput methods. The results were consistent with the automated screening results, indicating that all provided compounds reduced aggregation of G93A SOD1 in PC12 cells with similar efficacy and potency. The ability of provided compounds to induce expression of molecular chaperones was also tested using stably-transfected HeLa cells (HeLa hse-luc) expressing a luciferase reporter gene under the control of the human HSP70 promoter. This HeLa hse-luc reporter system was used previously to identify small-molecule activators of the heat shock response (Westerheide et al. J. Biol. Chem. 2004, 279(53), 56053-56060). The results showed that the five most potent provided compounds, at up to 100 μM, failed to induce luciferase activity in the HeLa hse-luc system, while positive control compounds celastrol and CdCl₂ strongly induced luciferase activity (FIG. 6). Provided compounds also failed to induce expression of multiple Hsp70, Hsp40, and Hsp90 genes as determined by RT-PCR. These results suggest that while provided compounds are likely to protect PC12 cells from G93A SOD1 by reducing its aggregation, this effect is not likely to be mediated by increasing the expression of molecular chaperones.

Since the CMB-003299 cytotoxicity of SOD1 protein aggregates may involve inhibition of proteasome activity, compounds that stimulate proteasome activity could reverse or prevent mutant SOD1-induced cytotoxicity. Thus, active compounds were tested for the ability to stimulate proteasome activity using a cell line expressing ubiquitin-conjugated YFP [Ubi-YFP 74]. In these cells, increased proteasome activity causes increased degradation of Ubi-YFP and decreased YFP fluorescence. Conversely, compounds that inhibit proteasome activity increase accumulation of Ubi-YFP and enhanced YFP fluorescence. As expected, MG132 augments YFP fluorescence intensity ˜3-fold compared to untreated controls (FIG. 7). The provided compounds (CMB-3299 or CMB-3319) strongly inhibit MG132-induced Ubi-YFP fluorescence, suggesting that these compounds stimulate proteasome activity. To demonstrate that these compounds are not simply blocking the action of MG132, a group of provided compounds were tested on a C. elegans strain which expresses mutant SOD1 in muscle cells. Protein aggregates are present in the absence of MG132 and aggregation is suppressed following treatment with a provided compound. These results suggest that the mechanism by which provided compounds protect cells against mutant SOD1-induced cytotoxicity is by stimulating the proteasome.

Example 3. Procedures and Protocols for Compound Characterization

Activation of Cellular Heat Shock Response.

HeLa cells, stably transfected with a luciferase reporter plasmid under control of the HSP70 promoter, were plated in a 96 well plate at a density of 7500 cells/100 μl. Following a 16 h incubation at 37° C./5% CO₂, compounds were added and cells incubated for an additional 8 h. Cells were lysed by the addition of 100 μl BrightGlo reagent (Promega) according to manufacturer's instructions and luciferase activity measured by quantifying luminescence signal. Cells were treated with test compounds at concentrations ranging from 10-100 μM celastrol or CdCl₂ serve as positive controls while DMSO is a negative control.

Proteasome Activity Assay.

HeLa cells (20,000/chamber) were plated on 8 chambered Tissue-tek coverglass pretreated with 1 mg/ml poly-D-lysine and allowed to adhere for 18 h at 37° C./5% CO₂. Cells were transfected with 0.2 μg each CMV-CFP and Ubi-YFP plasmids using Lipofectamine 2000 according to manufacturer's instructions. Cells were allowed to express CFP and Ubi-YFP for 18 h followed by a 6 h incubation with test compounds (25 μM). MG132 (1 μM) was added for a final 18 h incubation and Ubi-YFP degradation assessed by fluorescence microscopy. Fluorescence intensity of CFP and YFP was calculated on a cell-by-cell basis from captured images using AxioVision software (Zeiss). YFP fluorescence was normalized to CFP fluorescence.

Cytotoxicity Assay.

Nonspecific cytotoxicity was determined using PC12 and other cell lines in conventional dose response assays employing calcein-AM fluorescence as the indicator of cell viability. In addition, compounds could score a false positive by selectively reducing the synthesis of aggregated proteins (i.e., SOD1-YFP fusion). Reduction in SOD1 protein concentration was determined using a modification of the high content assay in which YFP fluorescence is measured on a plate reader prior to determining number of cells per well with the Arrayscan. Specific YFP activity, which is equivalent to SOD1 content per cell, was then calculated.

Expanded Assays for Aggregated Protein Spectrum.

Provided compounds are tested for efficacy in cell lines that express huntingtin protein aggregates instead of SOD1 (Kim et al., Nat. Cell. Biol. 2002, 4(10), 826-831; Matsumoto et al., J. Biol. Chem. 2005). Other active compound series are tested in these cells as well. If broader characterization is desired, analogous cell lines expressing tau, amyloid Aβ, and prion protein are constructed and similar experiments performed. In addition, a cell line that expresses TDP-43 and produces TDP-43 aggregates is constructed. TDP-43 is an aggregated protein that accumulates in neural cells in patients with sporadic ALS (Neumann et al. Science, 2006, 314(5796), 130-133; Arai et al., Biochem. Biophys. Res. Commun. 2006, 351(3), 602-611). Active compounds are tested for ability to prevent TDP-43 aggregation and/or reduce its associated cytotoxicity. Compounds that prevent TDP-43-associated cytotoxicity and/or aggregation are expected to have greater potential for efficacy in sporadic ALS patients.

Identification of Chemical Lead(s) Whose Predicted Pharmacological Properties are Suitable for Testing in Mice.

The most common and most rigorous approach to determine the toxicity and pharmacological properties of candidate pharmacological compounds relies on in vivo testing in laboratory animals. Because animal testing is both expensive and time consuming, many drug discovery organizations have turned to in vitro methods to analyze the pharmacological properties of compounds during structural optimization. This approach relies on miniaturized predictive in vitro ADMET assays that are amenable to high- to medium-throughput implementation. These methods have achieved increased popularity, both because animal models are limited in their ability to predict efficacy and toxicity in humans, and because regulatory agencies have begun to require human in vitro testing, such as human liver CYP450 inhibition assays, prior to human clinical trials. The need for methods of this type has also been motivated by the switch from animal disease models to target based in vitro methods for lead discovery (Kerns et al. Curr. Top Med. Chem. 2002, 2(1), 87-98; Di et al., Curr. Opin. Chem. Biol. 2003, 7(3) 402-408; Kassel et al., Curr. Opin. Chem. Biol. 2004, 8(3), 339-345). The in vitro ADMET approach is based on the use of a suite of chemical tests (compound integrity, compound solubility, compound aggregation, lipophilicity, pKa) and biological assays (Caco-2 and/or PAMPA assays, cytochrome P450 metabolism and inhibition, cardiac risk, and cytotoxicity) that assess the absorption, distribution, metabolism, excretion, and toxic effects of test compounds. The output from ADMET assays is used to identify and select for compounds with low predicted toxicity and desirable predicted pharmacological properties during SAR-based optimization. Compounds optimized by this approach are selected for analysis in the mouse model of ALS. The following suite of assays are performed:

Cytotoxicity: Cytotoxicity is determined in cultured cells.

Compound Purity: Each compound is subjected to chemical analysis to confirm molecular weight and determine purity. Only compounds >95% pure are used for further testing. Compounds <80% pure are re-purified and re-tested.

Compound Aggregation: Aggregation of screening hits is measured using dynamic light scattering.

Solubility: Because compounds are stored in DMSO, it is necessary to determine aqueous solubility of initial hit compounds and their analogs. High solubility in aqueous solution is necessary for high GI absorption, bioavailability, and for chemical formulation. Compounds should be soluble in aqueous solution at >10 μg/ml. Solubility of >50 μg/ml is preferred.

General Permeability: High membrane permeability is required for effective GI absorption and optimal bioavailability. Passive permeability is typically assessed in the PAMPA artificial membrane assay (Kansy et al., J. Med. Chem. 2002, 45(8), 1712-1722). Cell-based permeability determinations using the Caco-2 cell assay are more resource intensive but more predictive of active transport or efflux in vivo (Artursson et al., Adv. Drug. Deliv. Rev. 2001, 46(1-3), 27-43). Caco-2 assays are performed as needed during SAR development.

Blood Brain Barrier: CNS therapeutics must penetrate the blood-brain barrier (BBB) to achieve in vivo efficacy (Basak et al., Pharm Res. 1996, 13(5), 775-778). A QSAR model was developed for predicting in vivo BBB partitioning using the logarithm of the blood-brain concentration ratio as a diagnostic indicator. A 189 compound dataset was constructed from data in the literature (Rose et al., J. Chem. Inf. Comp. Sci. 2002, 42(3), 651-656; Pan et al., J. Chem. Inf. Comp. Sci. 2004, 44(6), 2083-2098) and compounds in the dataset entered as 2D structural drawings with ISIS/Draw and saved as mol files and converted into 3D structures using the Corina software prior to calculating molecular descriptors using Dragon. A Support Vector Machine (SVM) linear regression algorithm was used to generate & validate the model. The prediction accuracy (Q) for the SVM linear regression training model (n=166) and validation set (n=24) was 86.75 and 86.96%, respectively, confirming the validity of the model. Using this BBB predictive model, the potential of active compounds to cross the BBB is appraised early during development. Other BBB predictive models, including a variant of the PAMPA assay developed specifically for this purpose (Di et al., Eur. J. Med. Chem. 2003, 38(3), 223-232), is used as needed. Results of these experiments guide synthesis of compounds with appropriate ADME properties for use as CNS therapeutics.

Lipophilicity and pKa: Lipophilicity is determined via octanol-water partition at pH 7.4 (Hitzel et al., Pharm. Res. 2000, 17(11), 1389-1395) and pKa is determined by capillary electrophoresis and photodiode array detection (Ishihama et al., J. Pharm. Sci. 2002. 91(4), 933-942).

Metabolism (microsome, S9 fraction, CYP450): Liver Cytochrome P450 (CYP450) enzymes are the major route for xenobiotic metabolism and microsomal and hepatocyte stability is the best predictor of pharmacokinetic half-life. Cross-species comparisons of metabolism in liver microsomes can predict potential issues with liver toxicity in humans. Selected active compounds are tested in liver microsomes from efficacy species (mouse), toxicity species (rat, dog, monkey), and humans for metabolic stability.

Drug-drug interaction and cardiac risk potential: Data-mining algorithms and data compiled from the literature, are used to predict whether active compounds are likely to interact with and/or inhibit major Cytochrome P450's (1A2, 2C9. 2C19, 3A4, 2D6) (Kerns et al., Curr. Top. Med. Chem. 2002, 2(1), 87-98). Synthesized compounds are also tested directly for ability to bind and inhibit human CYP P450. If potential problems are indicated by these approaches, analog synthesis is directed towards developing alternative compounds. This approach allows for the assessment of cardiac safety, since hERG inhibition is assessed simultaneously on the same compounds. The hERG assay is done with the fast-patch methodology. hERG ion channel inhibition is implicated in greater than 90% of reported cases of cardiac toxicity, and is a common cause of after market drug failures and withdrawals. Information on hERG inhibition as well as inhibition of five major human CYP450s (1A2, 2C9. 2C19, 3A4, 2D6) allows for accurate prediction of potential drug-associated cardiac risk.

Plasma stability: Plasma stability of active compounds is assessed in efficacy species (mouse), toxicity species (rat, dog, monkey), and human cells.

Plasma protein binding: Plasma protein binding is examined in efficacy species (mouse), toxicity species (rat, dog, monkey), and human cells using ultrafiltration methodology.

The compounds identified were evaluated in the transgenic G93A ALS mouse model. ADME data was used to determine optimal route of administration. LD₅₀ and maximally-tolerated dose were determined, and that information was used to design and execute pharmacokinetic studies to assess brain bioavailability, and to guide choice of dosing regimen (i.e., frequency, dose, route). Three-dose basic efficacy studies were performed on compounds demonstrating acceptable tolerability and bioavailability. For compounds that demonstrate efficacy, a more complete preclinical study is performed and the efficacies of the test compound and previously characterized neuroprotective agents are compared. This may include further dose optimization, phenotype assessment, comparison with compounds of established efficacy, and analysis of brain tissue in treated animals.

Procedures

Subjects. In the present study, G93A SOD1 mice and littermate controls were bred from existing colonies at the Bedford VA Medical Hospital. The male G93A SOD1 mice were mated with B6SJL females and the offspring were genotyped by PCR using tail DNA. The number of SOD1 transgenes were assessed periodically by PCR to ensure that transgene copy number did not increase or decrease significantly over the course of time. Mice were housed in micro-isolator cages in complete barrier facilities. A 12 hour light-dark cycle was maintained and animals were given free access to food and water. Control and transgenic mice of the same age (±2 days) and from the same ‘f’ generation were selected from multiple litters to form experimental cohorts (n=20 per group). Standardized criteria for age and parentage were used for placing individual mice into experimental groups/cohorts. Wild type mice were used for initial toxicity, tolerability, and pharmacokinetic studies and ALS mice were used for one month tolerability studies.

Tolerability, Dosing, and Pharmacokinetics. The tolerable dose range and LD50 for each test compound was determined in wild type mice by increasing the dose b.i.d. one-fold each injection. The route of administration (p.o. by gavage or i.p.) and starting dose was based on solubility and other output from ADME studies. Initial pharmacokinetic (pK) studies were conducted by giving animals a single dose, sacrificing them after 30 min, 1 h, 2 h, 4 h, 6 h, or 12 h, and dissecting brains and spinal cords and determining drug concentration in the target tissue. Drug steady-state levels were determined in animals that have been dosed for 1 week prior to sacrifice. These data are used to optimize the dosing regimen for efficacy studies. Drug doses should achieve a desirable drug concentration in the brain and spinal cord of treated mice. Working doses at least 10-fold lower than the acute tolerability dose are preferable.

Efficacy studies. Efficacy is measured using endpoints that indicate neuroprotective function. These include reversal of degenerative lesions in the brain and neuronal tissues, improved motor function, increased body weight, and prolonged survival. Some mice cohorts are sacrificed at a predetermined time point, while others are sacrificed when they reach criteria for euthanasia.

Survival. Mice were observed three times daily (morning, noon, and late afternoon) throughout the experiment. Mice were euthanized when disease progression is sufficiently severe that they were unable to initiate movement and right themselves after gentle prodding for 30 seconds.

Body weights. Mice are weighed twice a week at the same time each day. Weight loss is a sensitive measure of disease progression in transgenic G93A SOD1 mice and of toxicity in transgenic and wild type mice.

Motor/behavioral. Quantitative methods of testing motor function are used including Rotarod and analysis of open field behavior. Decline of motor function is a sensitive measure of disease onset and progression.

Neuropathology. Selected cohorts (n=10) of treated and untreated G93A SOD1 mice are euthanized at 120 days for isolation and analysis of spinal cord tissue. For this purpose, mice are deeply anesthetized and perfused transcardially with 4% buffered paraformaldehyde at the desired time point. These and other studies are performed in a blinded manner, to avoid bias in interpretation of the results. Brains are weighed, serially sectioned at 50 μm and stained for quantitative morphology (cresyl violet), to assess protein aggregates, and to label ventral neurons. Remaining tissue samples/sections are stored for future use. Stereology is used to quantify ventral horn atrophy, neuronal atrophy, neuronal loss, and protein aggregate load.

Analysis. Data sets are generated and analyzed for each clinical and neuropathological measure. Effects on behavior and neuropathology are compared in treatment and control groups. Dose-dependent effects are assessed in each treatment group using multiple two-sided ANOVA tests. Multiple comparisons in the same subject groups are dealt with post hoc. Kaplan-Meier analysis was used for survival and behavioral function.

Neuronal quantitation. Serial lumbar spinal cord tissue sections (n=20) from L3-L5 spinal cord segments are used for gross spinal cord areas and neuronal analysis. Gross areas of the spinal cord sections are quantified from each experimental cohort using NIH Image. From the same sections, the ventral horn is delineated by a line from the central canal laterally and circumscribing the belly of gray matter. Absolute neuronal counts of Nissl-positive neurons are performed in the ventral horns in the lumbar spinal cord. Only those neurons with nuclei are counted. All counts are performed with the experimenter (JM) blinded to treatment conditions. Counts are performed using Image J (NIH) and manually verified and the data represent the average neuronal number from the sections used.

Interpretation. Compound efficacy is evaluated using behavioral and neuropathological endpoints. Results for the test compound are compared with results from compounds with established efficacy and neuroprotective action in the G93A SOD1 mouse model. These experiments directly test whether the provided compounds provide therapeutic benefit and, if so, the magnitude of the benefit. Along the way, useful information about solubility, administration, and toxicity are also obtained.

Example 4. Synthetic Routes

Synthetic schemes of the selected analogs of the general arylsulfanylpyrazolone scaffold are illustrated below.

^(a)Reagents and conditions: (a) benzaldehyde, HCl, rt, 5 min; (b) NH₂NH₂, EtOH, reflux, 1 h; (c) PBr₃, THF, rt, 6 h; (d) benzenethiol, K₂CO₃, DMF, 70° C., 18 h.

3-Benzylidenefuran-2,4(3H,5H)-dione (TC-I-49)

Tetronic acid (300 mg, 3 mmol) was added to benzaldehyde (1.0 mL, 9 mmol), and the resulting solution was stirred. HCl (37.7%, 0.1 mL) was added drop wise. The reaction mixture was vigorously stirred until it solidified. The solid product was crushed, soaked in hexane and washed with hexane. The crude product was purified by recrystallization (ethyl acetate/hexanes=8/2) to give compound TC-I-49 (0.27 g, 48%) as a yellow solid.

4-Benzylidene-3-(hydroxymethyl)-1H-pyrazol-5(4H)-one (TC-I-53)

To a suspension of ethanol (2 mL) and TC-I-49 (367 mg, 2 mmol) was added an ethanolic solution of hydrazine (2 N, 1 mL). The resulting suspension was refluxed for 1 h, during which time all of the TC-I-49 dissolved and a new precipitate formed. The resulting mixture was cooled in an ice-bath for 20 min. The white precipitate was filtered and washed with cold ethanol to give TC-I-53 (77 mg, 28%).

4-Benzylidene-3-(bromomethyl)-1H-pyrazol-5(4H)-one (TC-I-82)

PBr₃ (30 μl, 0.38 mmol) was added to a suspension of TC-I-53 (0.23 g, 1.1 mmol) in THF (5 mL) at 0° C. under N₂. The reaction mixture was warmed to room temperature after 5 min. Additional PBr₃ (30 μl, 0.38 mmol) was added after 1 h. The resulting suspension gradually became a solution and was stirred overnight. The reaction mixture was then quenched with brine, and the aqueous layer was extracted with CH₂Cl₂. The combined organic layer was washed with brine, dried over Na₂SO₄, and evaporated to dryness. TC-I-82 (0.125 g, 41%) was obtained by flash column chromatography (ethyl acetate/hexanes=1/4) as a yellow solid.

4-Benzylidene-3-(phenylthiomethyl)-1H-pyrazol-5(4H)-one (TC-I-91)

Benzenethiol (61 μL, 0.60 mmol) was added to a suspension of TC-I-82 (0.13 g, 0.50 mmol) and anhydrous potassium carbonate (0.42 g, 3.0 mmol) in DMF (2 ml) at room temperature. The reaction temperature was gently brought to 70° C. After the resulting suspension was stirred for 18 h, the reaction mixture was quenched with HCl (0.25 N), and the aqueous layer was extracted with EtOAc. The combined organic layer was washed with brine, dried over Na₂SO₄, and evaporated to dryness. TC-I-91 (40 mg, 27%) was obtained by flash column chromatography (ethyl acetate/hexanes=1/2) as a white solid.

^(a)Reagents and conditions: (a) ethyl 4-chloroacetoacetate, Et₃N, 0° C., 30 min; (b) NH₂NH₂, EtOH, reflux, overnight.

Ethyl 4-(4-chlorophenylthio)-3-oxobutanoate (TC-I-164)

4-Chlorothiophenol (1.1 g, 7.61 mmol) was mixed with ethyl 4-chloro-acetoacetate (0.95 mL, 7.00 mmol) in CH₂Cl₂ (100 mL) at 0° C. Triethyl amine (1.5 mL, 10.8 mmol) was then added drop wise. After the resulting suspension was stirred at 0° C. for another 30 min, the reaction mixture was poured into water, and the aqueous layer was extracted with EtOAc. The combined organic layer was washed by saturated NaHCO₃, HCl (0.25 N), brine, concentrated in vacuo, and purified by flash column chromatography (ethyl acetate/hexanes=1/9) to afford TC-1-164 (1.82 g, 96%) as light yellow oil. Exposure to hydrazine in refluxing ethanol, generated TC-II-165.

5-((4-Chlorophenylthio)methyl)-1H-pyrazol-3(2H)-one (TC-I-165)

Compound TC-I-164 (0.48 g, 1.76 mmol) was stirred in EtOH (5 mL), and an ethanolic solution of NH₂NH₂ (2 N, 0.88 mL, 1.76 mmol) was added. The resulting solution was refluxed for overnight under Ar, during which a precipitate formed. The reaction mixture was then cooled at room temperature. The precipitate was washed with cold EtOH and dried in vacuo to afford TC-I-165 (0.31 g, 72%) as a white solid.

Reagents and conditions: (a) TBHP, vanadyl acetylacetonate, CH₂Cl₂, room temp, overnight; (b) NH₂NH₂, EtOH, room temp, overnight.

Ethyl 4-(4-chlorophenylsulfinyl)-3-oxobutanoate (TC-II-65): Compound TC-I-164 (1.27 g, 4.66 mmol) was mixed with t-butyl hydrogen peroxide (70 wt % in water, 1.1 mL, 7.69 mmol) in CH₂Cl₂ (50 mL) at room temperature, and vanadyl acetylacetonate (0.1% mol) was added slowly. Extra t-butyl hydrogen peroxide (0.5 mL, 3.50 mmol) was added to the reaction mixture after 2 h. The resulting suspension was stirred overnight at room temperature. The reaction mixture was then concentrated in vacuum and purified by flash column chromatography (ethyl acetate/hexanes=1/4) to afford compound TC-II-65 (0.98 g, 73%) as a light yellow oil. Exposure to hydrazine in refluxing ethanol, generated TC-II-68.

Reagents and conditions: (a) TBHP, vanadyl acetylacetonate, CH₂Cl₂, room temp, overnight; (b) NH₂NH₂, EtOH, room temp, overnight.

Ethyl 4-(4-chlorophenylsulfonyl)-3-oxobutanoate (TC-II-64)

Compound TC-I-164 (3.00 g, 11.0 mmol) was mixed with t-butyl hydrogen peroxide (70 wt % in water, 1.5 mL, 10.50 mmol) in CH₂Cl₂ (50 mL) at room temperature, and vanadyl acetylacetonate (0.1% mol) was added slowly. Extra t-butyl hydrogen peroxide (6 mL, 41.94 mmol) was added to the reaction mixture after 2 h. The resulting suspension was stirred overnight at room temperature. The reaction mixture was then concentrated in vacuum and purified by flash column chromatography (ethyl acetate/hexanes=1/4) to afford compound TC-II-64 (1.61 g, 48%) as a light yellow oil. Exposure to hydrazine in refluxing ethanol, generated TC-II-70.

Reagents and conditions: (a) ethyl 4-chloroacetoacetate, Et₃N, 0° C., 30 min; (b) H₂O₂, AcOH, EtOAc, room temp, overnight; (c) NH₂NH₂, EtOH, room temp, overnight.

Ethyl 4-(4-chloro-2,5-dimethylphenylsulfonyl)-3-oxobutanoate (TC-II-171)

Compound TC-II-170 (4.68 g, 14.1 mmol) was mixed with AcOH (5 mL) in EtOAc (10 mL), and H₂O₂ (30% in water, 10 mL, 84.6 mmol) was added. The resulting solution was left stirring at room temperature for overnight after extra H₂O₂ (30% in water, 5 mL, 42.3 mmol) was added. The reaction mixture was then evaporated in vacuo and purified by flash column chromatography (ethyl acetate/hexanes=1/3) to afford TC-II-171 (4.34 g, 85%) as a light yellow oil. Exposure to hydrazine in refluxing ethanol, generated TC-II-172.

Reagents and conditions: (a) ethyl 4-chloroacetoacetate, NaH, dry THF, dry DMF, 70° C., overnight; (b) NH₂NH₂, EtOH, room temp, overnight.

Ethyl 4-(4-chlorophenoxy)-3-oxobutanoate (TC-II-48)

A solution of 4-chlorophenol (6.4 g, 50 mmol) in THF (25 mL) was treated with NaH (60% in mineral oil, 2 g, 50 mmol) at 0° C. In another flask, a solution of ethyl 4-chloroacetoacetate (10.21 mL, 75 mmol) in THF (25 mL) was treated NaH (60% in mineral oil, 3.5 g, 75 mmol) at −20° C. The resulting yellowish suspension was slowly added to the solution of sodium 4-chlorophenoxide, which was kept at 0° C. After the addition of DMF (10 mL), the reaction temperature was slowly raised to 70° C. After reaction mixture was stirred at 70° C. for overnight, it was cooled and evaporated to dryness. The residue was purified by flash column chromatography (ethyl acetate/hexanes=1/9) to afford TC-II-148 as a yellowish oil, which still contained some 4-chloroacetoacetate. No further purification was applied for the next step of synthesis. Exposure to hydrazine in refluxing ethanol, generated TC-II-150.

Reagents and conditions: (a) EtOAc, LDA, THF, −78° C. to rt, overnight; (b) NH₂NH₂, EtOH, rt, overnight.

Reagents and conditions: (a) NH₂NHMe, EtOH, room temp, overnight; (b) Me₂SO₄, CaO, MeOH, room temp, overnight

5-((4-Chlorophenoxy)methyl)-1,2-dimethyl-1H-pyrazol-3(2H)-one (TC-III-93)

Compound TC-III-87 (0.145 g, 0.61 mmol) was mixed with CaO (0.20 g, 3.57 mmol) and Me₂SO₄ (0.3 mL, 1.80 mmol) in MeOH (10 mL). The resulting suspension was left stirring at room temperature for overnight. The reaction mixture was then evaporated to dryness. The residue was purified by flash column chromatography (ethyl acetate/hexanes=2/1) to afford TC-III-93 (28.5 mg, 19%) as a white solid.

Reagents and conditions: (a) EtOAc, LDA, THF, −78° C. to rt, overnight; (b) NH₂NH₂, EtOH, rt, overnight.

4-Chlorophenyl ethyl malonate (TC-III-185)

EtOAc (0.63 mL. 6.44 mmol) was added to a solution of n-BuLi (1.6 M in hexanes, 9.2 mL, 14.72 mmol) and diisopropylamine (2.1 mL, 14.85 mmol) at 0° C. After 60 min of stirring, a THF solution of the acetyl chloride (1.31 g, 6.41 mmol) was added at −78° C. The reaction mixture was stirred at −78° C. for 1 h, then at room temperature for overnight. The resulting reaction solution was quenched with diluted HCl (0.25 M), and the aqueous layer was extracted with Et₂O. The combined organic layer was dried over Na₂SO₄ and concentrated in vacuo. The residue was purified by flash column chromatography (ethyl acetate/hexanes=1/9) to give TC-III-85 (0.41 g, 25%) as a yellowish oil.

^(a)Reagents and conditions: (a1) NaOEt, EtOH, 70° C., overnight; (a2) DIEA, DCM, rt, 30 min; (b) EtOAc, LiHMDS, THF, −78° C., 8 h; (c) NH₂NH₂, EtOH, rt, overnight.

2-(3,5-Dichlorophenoxy)-N-methoxy-N-methylacetamide (TC-IV-10), method a1

To a solution of phenol (5.27 g, 32.33 mmol) in EtOH (10 mL) was added NaOEt (21 wt % in EtOH, 12.1 mL, 32.41 mmol) at room temperature. The reaction mixture was stirred for 10 min. 2-Bromo-N-methoxy-N-methylacetamide (5.87 g, 32.25 mmol) was then gently added at room temperature. After the resulting solution was stirred at 70° C. for overnight, the reaction mixture was cooled, poured into HCl (0.25 M), and the aqueous layer was extracted with EtOAc. The combined organic layer was concentrated in vacuo and reconstituted in CHCl₃. The precipitate was filtered and washed with CHCl₃. Wienreb amide TC-IV-10 (4.53 g, 53%) was obtained as a white solid.

2-(3,5-Dichlorophenoxy)-N-methoxy-N-methylacetamide (TC-IV-10), method a2

To a solution of N,O-dimethylhydroxylamine HCl salt (5.3 g, 54.33 mmol) in DCM (250 mL) was added DIEA (24 mL, 137.8 mmol) at room temperature. The reaction mixture was stirred for 5 min. Acetyl chloride (13.0 g, 54.28 mmol) was then added in DCM drop by drop at 0° C. The reaction mixture was stirred at room temperature for another 30 min. The resulting reaction solution was washed with HCl (1 N) and concentrated under vacuum. The crude solid product was washed with Et₂O to give Weinreb amide TC-IV-10 (12 g, 84%) as a white solid.

Ethyl 4-(3,5-dichlorophenoxy)-3-oxobutanoate (TC-IV-12)

EtOAc (0.9 mL. 9.19 mmol) was added to a solution of LiHMDS (1 N in THF, 21 mL, 21 mmol) at 0° C. and stirred. After 60 min, a THF solution of the Wienreb amide TC-IV-10 (2.4 g, 9.19 mmol) was added at −78° C. After the resulting solution was stirred at −78° C. for 8 h, the reaction mixture was quenched with diluted HCl (0.25 N), and the aqueous layer was extracted with Et₂O. The combined organic layer was dried over Na₂SO₄ and concentrated in vacuo. The residue was purified by flash column chromatography (ethyl acetate/hexanes=1/9) to give TC-IV-12 (1.03 g, 39%) as a white solid.

5-((3,5-Dichlorophenoxy)methyl)-1H-pyrazol-3(2H)-one (TC-IV-19)

Ethanolic hydrazine (2 N, 2.5 mL, 5 mmol) was added to a solution of TC-IV-12 (1.5 g, 5.15 mmol) in EtOH (25 mL). The resulting solution was stirred at room temperature for overnight. The reaction mixture was then evaporated in vacuo, purified by flash column chromatography (ethyl acetate/hexanes=1/2) and recrystallized in ethyl acetate/hexanes to give the final product TC-IV-19 (0.368 g, 28%) as a white crystal.

Reagents and conditions: (a) PdCl₂(PPh₃), K₂CO₃, dioxane, H₂O, 100° C., 16 h; (b) NaOEt, EtOH, 70° C., overnight; (c) EtOAc, LiHMDS, THF −78° C., overnight; (d) NH₂NH₂, EtOH, rt, overnight.

Biphenyl-3-ol (TC-IV-119)

3-Bromophenol (1.0 g, 5.78 mmol), phenylboronic acid (1.4 g, 11.48 mmol), potassium carbonate (2.0 g, 14.47 mmol), and PdCl₂(PPh₃) (1/200 eq.) were added to a solution of dioxane/H₂O (20 mL/5 mL). The resulting solution was refluxed for 16 h. The reaction mixture was then partitioned between Et₂O and water, and the aqueous phase was extracted with Et₂O. The combined organic layer was evaporated to dryness and purified by flash column chromatography (ethyl acetate/hexanes=1/9) to give TC-IV-119 (1.02 g, 100%) as a transparent oil.

TC-IV-120

3,5-Dibromophenol (1.0 g, 3.97 mmol), phenylboronic acid (2 g, 16.4 mmol), potassium carbonate (2.7 g, 19.5 mmol), and PdCl₂(PPh₃) (1/200 eq.) were added to a solution of dioxane/H₂O (20 mL/5 mL). The resulting solution was refluxed for 16 h. The reaction mixture was then partitioned between Et₂O and water, and the aqueous phase was extracted with Et₂O. The combined organic layer was evaporated to dryness and purified by flash column chromatography (ethyl acetate/hexanes=1/9) to give TC-IV-120 (0.83 g, 83%) as a transparent oil.

Reagents and conditions: (a) DIEA, DCM, rt, 48 h; (b) K₂CO₃, acentone, 50° C., overnight; (c) EtOAc, LiHMDS, THF −78° C., 16 h; (d) NH₂NH₂, EtOH, rt, overnight; (e) HBr, PhOH, H₂O, 100° C., 8 h; (f) R_(A)CHO, NaBH(OAc)₃, DCM, rt, overnight.

N-(3,5-Dichlorophenyl)benzenesulfonamide (TC-IV-145)

Benzenesulfonyl chloride (1.74 mL, 13.57 mmol) and DIEA (0.34 mL, 2.49 mmol) were added to a solution of 3,5-dichloroaniline (2.0 g, 12.34 mmol) in DCM (50 mL). The resulting solution was stirred at room temperature for 48 h, during which a precipitate was formed. The reaction mixture was then evaporated to dryness and purified by flash column chromatography (ethyl acetate/hexanes=1/9) to give TC-IV-145 (1.90 g, 51%) as a yellow solid.

2-(N-(3,5-Dichlorophenyl)phenylsulfonamido)-N-methoxy-N-methylacetamide (TC-IV-146): To a solution of TC-IV-145 (1.90 g, 6.29 mmol) in acetone (30 mL) was added 2-bromo-N-methoxy-N-methylacetamide (1.14 g, 6.26 mmol) and potassium carbonate (0.86 g, 6.22 mmol) at room temperature. After the resulting suspension was stirred at 50° C. for overnight, the reaction mixture was concentrated in vacuo and purified by flash column chromatography (ethyl acetate/hexanes=1/4) to give the Wienreb amide TC-IV-146 (1.15 g, 44%) as a yellow solid.

Ethyl 4-(N-(3,5-dichlorophenyl)phenylsulfonamido)-3-oxobutanoate (TC-IV-147)

EtOAc (0.28 mL. 2.86 mmol) was added to a solution of LiHMDS (1 N in THF, 6.3 mL, 6.3 mmol) at −78° C. and stirred. After 60 min, a THF solution of the Weinreb amide TC-IV-146 (1.15 g, 2.86 mmol) was added. After the resulting solution was stirred at −78° C. for overnight, the reaction mixture was quenched with diluted HCl (0.25 N), and the aqueous layer was extracted with Et₂O. The combined organic layer was dried over Na₂SO₄ and concentrated in vacuo. The residue was purified by flash column chromatography (ethyl acetate/hexanes=1/2) to give crude TC-IV-147 (0.60 g, 48%) as a yellow oil.

N-(3,5-Dichlorophenyl)-N-((5-oxo-2,5-dihydro-1H-pyrazol-3-yl)methyl)benzenesulfonamide (TC-IV-150): Ethanolic hydrazine (2 N, 0.69 mL, 1.38 mmol) was added to a solution of TC-IV-147 (0.60 g, 1.39 mmol) in EtOH (10 mL). After the resulting solution was stirred at room temperature for overnight, the reaction mixture was evaporated in vacuo and purified by flash column chromatography (ethyl acetate/hexanes=1/1) to give TC-IV-150 (0.20 g, 32%) as a white solid.

5-((3,5-Dichlorophenylamino)methyl)-1H-pyrazol-3(2H)-one (TC-IV-154): TC-IV-150

(30 mg, 0.068 mmol) and phenol (60 mg, 0.64 mmol) were added to a solution of HBr in water (48%, 0.75 mL). After the resulting suspension was stirred at 100° C. for 8 h, the reaction mixture was partitioned between water and EtOAc, and the aqueous layer was extracted with EtOAc. The combined organic layer was evaporated to dryness and purified by flash column chromatography (ethyl acetate) to give TC-IV-154 (10 mg, 57%) as a white solid.

Reagents and conditions: (a) K₂CO₃, n-BuOH, reflux, 72 h; (b) K₂CO₃, acentone, 50° C., overnight; (c) EtOAc, LiHMDS, THF −78° C., 16 h; (d) NH₂NH₂, EtOH, rt, overnight.

1-(3,5-Difluorophenyl)piperazine (TC-IV-174)

Bis(2-chloroethyl)amine hydrochloride (2.07 g, 11.60 mmol) was added to a solution of 3,5-difluoroaniline (1.50 g, 11.62 mmol) in n-BuOH (20 mL). After the resulting solution was refluxed for 48 h, anhydrous potassium carbonate (1.61 g, 11.62 mmol) was added. After being refluxed for another 24 h, the reaction mixture was cooled, partitioned between water and CHCl₃, and the aqueous layer was extracted with CHCl₃. The combined organic layer was washed with water, dried over Na₂SO₄, and evaporated to dryness. Et₂O and 1 N HCl/EtOH were added to the residue, and the precipitate was filtered to give TC-IV-174 (1.17 g, 30%) as a white solid.

Reagents and conditions: (a) NiCl₂(dppp), THF, 60° C., 6 h; (b) (1) BBr₃, DCM, −78° C. to rt, 1 h; (2) H₂O, −78° C. to rt, 1 h.

Scheme 14 illustrates the use of Kumada couplings to access synthons wherein R⁴ is cyclic aliphatic.

Reagents and conditions: (a) K₂CO₃, n-BuOH, reflux, 48° C.; (b) K₂CO₃, acetone, 50° C., overnight; (c) EtOAc, LiHMDS, THF, −78° C., 16 h; (d) NH₂NH₂, EtOH, rt, overnight.

TABLE 2 ¹H NMR data for selected compounds. Structure ¹H NMR

¹H NMR (500 MHz, DMSO-d₆, δ): 11.62 (br s, 1H), 9.72 (br s, 1H), 7.57 (s, 1H), 7.46 (s, 1H), 5.39 (s, 1H), 4.15 (s, 2H), 2.30 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.29 (s, 1H), 8.03 (s, 1H), 7.68-7.18 (m, 10H), 5.19 (dd, J = 32.0, 16.5 Hz, 2H)

¹NMR (500 MHz, acetone-d₆, δ): 10.89 (s, 1H), 8.03 (s, 1H), 7.73 (d, J = 6.50, 2H), 7.78-7.22 (m, 7H), 5.22 (dd, J = 16.0, 22.0 Hz)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.54 (br s, 1H), 9.55 (br s, 1H), 7.34-7.29 (m, 4H), 7.19 (t, J = 7.0 Hz, 1H), 5.31 (s, 1H), 4.07 (s, 2H)

1H NMR (500 MHz, DMSO-d₆, δ): 11.22 (br s, 1H), 10.07 (br s, 1H), 7.33-7.26 (m, 4H), 5.34 (s, 1H), 4.04 (s, 2H), 1.25 (s, 9H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11. 64 (br s, 1H), 9.52 (br s, 1H), 8.13 (d, J = 8.5 Hz, 2H), 7.55 (d, J = 8.5 Hz, 2H), 5.41 (s, 1H), 4.26 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.55 (br s, 1H), 9.47 (br s, 1H), 7.36 (s, 4H), 5.31 (s, 1H), 4.08 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.45 (br s, 1H), 9.79 (br s, 1H), 7.48 (d, J = 8.5 Hz, 2H), 7.28 (d, J = 8.5 Hz, 2H), 5.32 (s, 1H), 4.08 (s, 2H)

¹H NMR (400 MHz, DMSO-d₆, δ): 10.66 (br s, 1H), 7.59 (s, 1H), 7.52 (d, J = 8.4 Hz, 1H), 7.30 (d, J = 8.0 Hz, 1H), 5.34 (s, 1H), 4.14 (s, 2H)

¹H NMR (400 MHz, DMSO-d₆, δ): 9.92 (br s, 1H), 7.63 (s, 1H), 7.47-7.39 (m, 2H), 5.38 (s, 1H), 4.15 (s, 2H)

¹H NMR (400 MHz, DMSO-d₆, δ): 7.20 (d, J = 8.8 Hz, 2H), 6.65 (d, J = 8.8 Hz, 2H), 5.20 (s, 1H). 3.83 (s, 2H), 2.88 (s, 6H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.67 (br s, 1H), 7.67 (d, J = 8.5 Hz, 2H), 7.45-7.36 (m, 6H), 7.24 (t, J = 7.5 Hz, 1H), 5.46 (s, 1H), 4.11 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.52 (br s, 1H), 9.40 (br s, 1H), 7.40-7.37 (m, 2H), 7.17 (t, J = 8.8 Hz, 2H), 5.27 (s, 1H), 4.03 (s, 1H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.55 (br s, 1H), 9.38 (br s, 1H), 7.16 (s, 1H), 7.06 (d, J = 7.5 Hz, 1H), 6.90 (d, J = 7.0 Hz, 1H), 5.33 (s, 1H), 4.03 (s, 2H), 2.25 (s, 3H), 2.19 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.45 (br s, 1H), 9.36 (br s, 1H), 7.29 (d, J = 8.5 Hz, 2H), 6.89 (d, J = 9.0 Hz, 2H), 5.22 (s, 1H), 3.93 (s, 2H), 3.73 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.49 (br s, 1H), 9.75 (br s, 1H), 7.62 (d, J = 8.0 Hz, 2H), 7.54 (d, J = 9.0 Hz, 2H), 5.17 (s, 1H), 4.13-3.99 (m, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.24 (br s, 1H), 7.75 (d, J = 9.0 Hz, 2H), 7.67 (d, J = 8.5 Hz, 2H), 5.21 (s, 1H), 4.56 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.45 (br s, 1H), 9.35 (br s, 1H), 7.55 (d, J = 8.5 Hz, 2H), 7.38 (t, J = 8.0 Hz, 1H), 5.12 (s, 1H), 4.01 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.56(br s, 1H), 9.47 (br s, 1H), 7.32 (s, 1H). 7.26 (s, 1H), 5.33 (s, 1H), 4.05 (s, 2H), 2.27 (s, 3H), 2.19 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.52 (br s, 1H), 9.50 (br s, 1H), 7.58 (s, 1H), 7.37 (s, 1H), 5.22 (s, 1H), 4.03- 3.93 (m, 2H), 2.35 (s, 3H), 2.15 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.57 (br s, 1H), 9.41 (br s, 1H), 7.50 (m, 2H), 7.25-7.21 (m, 1H), 5.35 (s, 1H), 4.12 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.60 (br s, 1H), 9.54 (br s, 1H), 7.46-7.17 (m, 4H), 5.39 (s, 1H), 4.14 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.60 (br s, 1H), 9.54 (br s, 1H), 7.40-7.22 (m, 4H), 5.33 (s, 1H), 4.13 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.57 (br s, 1H), 9.44 (br s, 1H), 7.39 (s, 3H), 5.34 (s, 1H), 4.18 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.42 (br s, 1H), 9.58 (br s, 1H), 7.35 (dd, J = 28.0, 8.5 Hz, 4H, 5.35 (s, 1H), 3.70 (s, 2H), 3.49 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.48 (br s, 1H), 9.48 (br s, 1H), 7.36 (s, 4H), 5.30 (s, 1H), 4.08 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 10.88 (br s, 1H), 7.35 (s, 4H), 5.24 (s, 1H), 3.99 (s, 2H), 3.43 (s, 3H)

¹H NMR (500 MHz, CDCl₃, δ ): 3.88 (s, 2H), 3.32 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.39 (br s, 1H), 9.52 (br s, 1H), 7.66-7.34 (m, 9H), 5.36 (s, 1H), 4.12 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.53 (br s, 1H), 9.37 (br s, 1H), 7.37 (d, J = 8.0 Hz, 1H), 7.27 (d, J = 7.5 Hz, 1H), 7.20-7.14 (m, 2H), 5.29 (s, 1H), 4.02 (s, 2H), 1.15 (d, J = 6.5 Hz, 6H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.50 (br s, 1H), 9.40 (br s, 1H), 7.28 (t, J = 7.8 Hz, 2H), 6.94-6.90 (m, 3H), 5.39 (s, 1H), 4.08 (t, J = 6.8 Hz, 2H), 3.69 (s, 2H), 2.82 (t, J = 6.5 Hz, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.54 (br s, 1H), 9.36 (br s, 1H), 7.36-7.14 (m, 4H), 5.31 (s, 1H), 4.04 (s, 2H), 2.63 (q, J = 7.4 Hz, 2H), 1.12 (t, J = 7.5 Hz, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.79 (br s, 1H), 9.56 (br s, 1H), 7.33 (d, J = 9.0 Hz, 2H), 7.02 (d, J = 9.0 Hz, 2H), 5.52 (s, 1H), 4.92 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.37 (br s, 1H), 9.72 (br s, 1H), 7.61 (d, J = 8.0 Hz, 2H), 7.46 (d, J = 8.0 Hz, 2H), 4.48 (s, 2H), 3.29 (s, 1H), 2.71 (q, J = 7.5 Hz, 2H), 1.21 (t, J = 7.5 Hz, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.56 (br s, 1H), 9.48 (br s, 1H), 7.64 (d, J = 7.5 Hz, 2H), 7.44 (m, 2H), 5.18 (s, 1H), 4.52 (s, 2H), 2.67 (t, J = 7.5 hz, 2H), 1.60-1.54 (m, 2H), 1.33-1.26 (m, 2H), 0.89 (t, J = 7.3 Hz, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.62 (br s, 1H), 9.59 (br s, 1H), 7.67 (s, 1H), 7.54 (s, 1H), 5.24 (s, 1H), 4.49 (s, 2H), 2.47 (s, 3H), 2.33 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.79 (br s, 1H), 9.55 (br s, 1H), 7.18 (t, J = 7.8 Hz, 1H), 6.83-6.79 (m, 3H), 5.52 (s, 1H), 4.89 (s, 2H), 2.56 (q, J = 7.5 Hz, 2H), 1.16 (t, J = 7.5 Hz, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.72 (br s, 1H), 9.50 (br s, 1H), 7.20 (t, J = 8.0 Hz, 1H), 6.97-6.80 (m, 3H), 5.52 (s, 1H), 4.91 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.75 (br s, 1H), 9.47 (br s, 1H), 7.17 (t, J = 7.5 Hz, 1H), 6.80-6.75 (m, 3H), 5.54 (s, 1H), 4.90 (s, 2H), 1.54 (m, 2H), 1.26-1.23 (m, 26H), 0.85 (t, J = 5.8 Hz, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.82 (br s, 1H), 9.54 (br s, 1H), 7.16 (s, 1H), 7.12 (d, J = 1.5 Hz, 2H), 5.53 (s, 1H), 4.99 (s, 2H)

. ¹H NMR (500 MHz, DMSO-d₆, δ): 11.62 (br s, 1H), 9.55 (br s, 1H), 7.77-7.36 (m, 2H), 5.26 (s, 1H), 4.70 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.75 (br s, 1H), 9.50 (br s, 1H), 7.10 (d, J = 8.0 Hz, 2H), 6.89 (d, J = 8.5 Hz, 2H), 5.50 (s, 1H), 4.87 (s, 2H), 2.54-2.51 (m, 2H), 1.13 (t, J = 7.5 Hz, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.79 (br s, 1H), 9.51 (br s, 1H), 7.52 (d, J = 9.5 Hz, 1H), 7.32 (d, J = 2.5 Hz, 1H), 7.02 (dd, J = 9.0, 2.5 Hz, 1H), 5.56 (s, 1H), 4.98 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.62 (br s, 1H), 9.50 (br s, 1H), 7.99 (s, 2H), 7.86 (s, 1H), 5.35 (s, 1H), 4.31 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 10.95 (s, 1H), 7.13 (s, 1H), 7.10 (s, 2H), 5.41 (s, 1H), 4.88 (s, 2H), 3.49 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 10.98 (br s, 1H), 7.30 (d, J = 8.5 Hz, 2H), 7.00 (d, J = 8.5 Hz, 2H), 5.40 (s, 1H), 4.82 (s, 2H), 3.48 (s, 3H)

¹H NMR (500 MHz, CDCl₃, δ ): 7.22-7.19 (m, 2H), 6.93- 6.90 (m, 2H), 5.60 (s, 1H), 4.91 (s, 2H), 3.86 (s, 3H), 3.61 (s, 3H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.82 (br s, 1H), 9.53 (br s, 1H), 6.80-6.79 (m, 3H), 5.56 (s, 1H), 4.95 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.80 (br s, 1H), 9.52 (br s, 1H), 7.39 (s, 1H), 7.28 (m, 2H), 5.55 (s, 1H), 4.99 (s, 1H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.78 (br s, 1H), 9.50 (br s, 1H), 7.26-7.23 (m, 2H), 7.14-7.13 (m, 1H), 7.02-7.00 (m, 2H), 5.58 (s, 1H), 4.96 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.80 (br s, 1H), 9.50 (br s, 1H), 7.67-6.99 (m, 9H), 5.55 (s, 1H), 5.02 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.82 (br s, 1H), 9.50 (br s, 1H), 7.76 (d, J = 8.0 Hz, 4H), 7.50-7.38 (m, 7H), 7.27 (s, 2H), 5.60 (s, 1H), 5.13 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.56 (br s, 1H), 9.39 (br s, 1H), 7.76-7.55 (m, 6H), 7.14 (s, 2H), 5.22 (s, 1H), 4.67 (s, 2H)

¹H NMR (500 MHz, DMSO-d₆, δ): 11.56 (br s, 1H), 9.52 (br s, 1H), 6.64-6.59 (m, 3H), 5.35 (s, 1H), 4.10 (d, J = 5.0 Hz, 2H)

Example 6. Biological Activity of Synthesized Arylsulfanylpyrazolone Analogs

Compounds synthesized above underwent a mutant SOD1 protein aggregation-induced toxicity protection screen and a direct protein aggregation high content assay. Results differ within a reasonable range from week to week due to bio-variation, however, relative potencies of the analogs were reproducible.

TABLE 3 Best Corresponding Corresponding EC50 (uM) after Entry Structure EC50 (μM) 3299 EC50 (μM) % viability Normalization 1

0.4 2

>32 3

6.85 0.27 77 10.1 4

5.38 0.93 150 2.31 5

5.59 0.93 136 2.4 6

4.49 0.93 93 1.93 7

4.24 0.93 94 1.8 8

2.6 0.55 113 1.89 9

1.58 0.55 124 1.15 10

1.65 77 11

5.11 0.59 109 3.46 12

4.73 0.55 104 3.44 13

0.22 77 14

4.21 0.93 102 1.81 15

>32 16

6.92 0.59 110 4.7 17

0.26 0.11 142 0.95 18

0.43 0.44 140 0.39 19

4.47 0.62 123 2.88 20

1.61 68 21

0.84 0.11 123 3.05 22

0.25 0.09 148 1.11 23

0.08 0.19 134 0.17 24

0.3 0.41 129 0.29 25

4.14 75 26

7.97 0.59 121 5.4 27

9.44 0.93 115 4.06 28

0.4 0.33 106 0.48 29

6.21 0.33 97 7.52 30

2.06 0.33 106 2.5 31

0.57 0.35 131 0.65 32

0.69 0.35 117 0.79 33

3.43 1.79 120 0.77 34

0.99 0.44 101 0.9 35

0.75 0.44 103 0.68 36

0.99 0.44 93 0.9 37

2.28 0.62 116 1.47 38

1.12 0.62 125 0.72 39

1.06 0.49 141 0.87 40

2.08 0.37 66 2.24 41

0.05 0.3 129 0.067 42

0.55 0.72 123 0.31 43

0.36 0.19 130 0.76 44

0.67 0.19 132 1.41 45

3.29 0.67 88 1.96 46

0.13 0.09 136 0.58 47

0.13 0.09 120 0.58 48

6.67 0.52 109 5.13 49

7.6 0.52 107 5.85 50

3.21 1.2 125 1.07 51

1.54 1.2 125 0.51 52

3.06 1.2 144 1.02 53

8.53 1.2 96 2.84 54

11.08 1.2 68 3.7 55

9.04 2.52 111 1.43 56

2.11 2.52 128 0.33 57

6.2 58

4.2 59

>32

In vitro ADME study of CMB-003319. CMB-003319 was evaluated for its in vitro ADME properties. The study showed that CMB-003319 has a medium metabolic potential, medium CaCO-2 permeability, poor plasma stability, and medium aqueous-solubility.

Rat liver microsomal stability study of TC-I-165. TC-I-165 was applied for an NADPH dependent rat liver microsomal stability study by HPLC. Preliminary results showed that TC-I-165 has poor microsomal stability like CMB-003319. The test (TC-I-165), positive control (minaprine), and internal standard (haloperidol) are shown in FIG. 11.

Microsomal metabolite study of TC-I-165. TC-I-165 was used in a NADPH dependent rat liver microsomal metabolite study by HPLC. TC-II-68 and TC-II-70 were proposed as possible metabolites and prepared before the study. Results showed that only TC-II-68 was a direct metabolite.

Microsomal metabolite study of TC-I-165. TC-II-125 was prepared as a double ¹⁵N isotope labeled TC-I-165. TC-I-165, TC-II-125, and TC-II-68 were sent for NADPH dependent rat liver microsomal metabolite determination. The results showed that during the first hour the only direct metabolite from TC-I-165 was TC-II-68, with no nitrogen loss on the pyrazolone ring.

Rat liver microsomal stability of TC-II-70. TC-II-70 was applied for an NADPH dependent rat liver microsomal stability test by HPLC. The results showed that TC-II-70 is much more stable compared with TC-I-165 for the first hour of microsomal metabolism.

In vitro ADME properties of analogs. Compounds were sent for in vitro ADME tests to evaluate their ADME properties. By substituting the thioether linkage with an ether linkage or a sulfone linkage in the arylsulfanylpyrazolone scaffold, the microsomal stability and aqueous-solubility were largely improved.

In vitro ADME study of CMB-087229. CMB-087229 was sent for an evaluation of its in vitro ADME properties. The study showed that CMB-087229 has a potency (ED₅₀) of 74 nM, medium human metabolic potential (T_(1/2)=93 minutes), medium mouse metabolic potential (T_(1/2)=36 minutes), high predicted CaCO-2 permeability (A-B=37×10⁻⁶ cm/s), medium plasma stability (T_(1/2)=17 minutes), and aqueous solubility of 250 μM. CMB-087229 has a metabolic half-life in rats of approximately 2 hours.

UV Spectra and Chromatography

Using a UV/VIS spectrometer (Perkin Elmer, Lamda 10), samples were scanned from 200-500 nm to determine the maximum UV absorbance. A wavelength of 260 nm was found to be optimal for HPLC monitoring. Samples were analyzed with a Beckman HPLC using a 166 UV detector coupled to a reverse phase C18 analytical column (Phenomenex, Luna 5μ C18 (2), 250*4.60 mm). After separation of the samples on the C18 column using an acetonitrile-water HPLC program, peaks were analyzed by 32 Karat™ software, version 5.1.

Microsomal Stability Study

Test agents (15 μM) were incubated in Eppendorf tubes with mouse microsomes (pooled male rat liver microsomes (Sprague Dawley), BD Science) at 37° C. Each reaction mixture was carried out in PBS (pH 7.4), which contained 1 mg/mL microsomal protein with 1.3 mM NADP⁺, 3.3 mM glucose-6-phosphate, 0.4 U/mt glucose-6-phosphate dehydrogenase, and 3.3 mM magnesium chloride. A control using minaprine was run to test the activity of the microsomal activity. After 0 and 20 minutes incubation, 40 μL of acetonitrile was added to quench the reactions. The reaction mixture was vortexed and incubated in an ice bath for 2 h. Haloperidol (100 μL, 100 μM) was added to every test tube as an internal standard. The samples were diluted in water and centrifuged to remove the precipitated protein. The supernatant solutions were loaded for solid phase extraction. Extraction fractions were evaporated and reconstituted for HPLC analysis.

Excel was used for data processing. The Response Ratio (RR) was calculated by dividing the peak area of the analyte by the peak area of the internal standard. Data suggest that TC-I-165 has low NADPH dependent rat liver microsomal stability.

TABLE 4 Microsomal stability data processing Sample Name RR Mean % Mean ± S.E. Mina 0 min 22.88  100 ± 7.11 Mina 20 min 13.54 59.2 ± 14.9 TC-I-165 0 min 2.529  100 ± 26.4 TC-I-165 20 min 0.314 12.4 ± 0.89 NADPH Rat Liver Microsomal Metabolites Study for TC-I-165 Test Methods

TC-I-165 was used for a NADPH dependent rat liver microsomal metabolites study, and the corresponding sulfoxide, TC-II-68, and sulfone, TC-II-70, also were prepared (FIG. 14).

Experiments were generally carried out according to the general procedure from the microsomal stability study of TC-I-165. After 0, 5, 10, 20, 40, and 60 minutes incubation with rat liver microsome, 50 μL acetonitrile was added to quench reactions. The reaction mixture was vortexed and incubated in an ice bath for 2 h. The samples were centrifuged to remove the precipitated protein. The supernatant solutions were loaded directly for HPLC analysis.

Data and Results

TC-II-68 was a metabolite from TC-I-165 after 60 minutes of NADPH dependent rat liver microsome incubation. TC-II-70 is not a metabolite. Only one new peak was observed from the microsomal residue of TC-I-165. Using the same HPLC program (25% acetonitrile, isocratic, 30 minutes), the retention time of the new peak was approximately identical to the one from TC-II-68. The retention time of TC-II-70 was well seperated from that of the new peak (see FIGS. 15-20).

Rat Liver Microsomal Stability Studies of TC-II-70

Test Methods

TC-II-70 was used in a NADPH dependent rat liver microsomal stability study. The test (TC-II-70), positive control (minaprine), negative control (warfarin), and internal standard (haloperidol) compounds in this experiment are listed in FIG. 21. The experiment was carried out mostly according to the general procedure from the microsomal stability study of TC-I-165. After 0, 20, and 40 minutes incubation, 100 μL acetonitrile was added to quench reactions. The reaction mixture was vortexed and incubated in an ice bath for 2 h. Haloperidol (50 μL, 100 μM) was added to every test tube as an internal standard. The samples were centrifuged to remove the precipitated protein. The supernatant solutions were loaded directly for HPLC analysis.

Results

TC-II-70 is more stable in a NADPH dependent rat liver microsomal stability study compare with its sulfide, TC-I-165 (FIGS. 22-25). Table 5 shows results of microsomal stability data processing.

TABLE 5 Sample Name RR Mean % Mean ± S.E. Mina 5 μM 0 min 0.711  100 ± 11.5 Mina 5 μM 40 min 0.321 45.2 ± 8.1  TC-II-70 15 μM 0 min 0.237  100 ± 12.6 TC-II-70 15 μM 20 min 0.261  109 ± 13.3 TC-II-70 15 μM 40 min 0.201 84.8 ± 21.8 War 15 μM 0 min 0.488  100 ± 7.75 War 15 μM 60 min 0.470 96.1 ± 7.66 Blood Brain Barrier Studies

Preliminary blood brain barrier (BBB) penetration experiment. An in vivo BBB penetration experiment was carried out for CMB-087229. CMB-003319 was used as the internal standard due to its structural similarity to CMB-003299. CMB-087229 was formulated in 100 μL DMSO in 2 mL phosphate buffered saline. Blood concentration of CMB-087229 (MTD of 75 mg/kd IP) 1 hour following a single 1 mg IP dose was approximately 10 nM. Brain concentration of CMB-087229 l hour following a single 1 mg IP dose was approximately 120 nM. After four hours, concentration in the brain was 194 μM. At 3 hours, plasma concentration measured 342 μM. At 6 hours, plasma concentration measured 347 μM. At 12 hours, plasma concentration measured 248 μM. At 24 hours, plasma concentration measured 1.68 μM. CMB-087229 reaches approximately 55% of the blood level in the brain.

Brain Uptake Procedure

CMB-087229 Mice Brain and Plasma Data CMB-087229 (1 mg/kg) was administrated to mice (Tg6799 colony with B6/SJL background) by intraperitoneal injection in a 60% PBS and 40% dimethyl sulfoxide solution. At 10 minutes after compound administration the mice were sacrificed. Blood was harvested and plasma was transferred to flash freeze in liquid nitrogen after centrifugation. Mice were perfused. The brain was homogenized in 100% acetonitrile. CMB-003319 (0.5 μg, 1.73 nmol) was added as an internal standard. The homogenates were centrifuged at 12000×g for 12 min, and the supernatant was evaporated. The residue was reconstituted in 33.3% acetonitrile. Solid phase extraction followed by LCMS (API 300 liquid chromatography-tandem mass spectrometry system, Applied Biosystems, Foster City, Calif.; Agilent 1100 series HPLC system, Agilent Technologies, Wilmington, Del.) was used to quantify the amount of CMB-087229 in mouse brain. Solid-phase extraction cartridges (Sep-Pak C18, Water Associates, Milford, Mass.) were washed with 1 mL acetonitrile and equilibrated with 1 mL of water. The reconstituted supernatant was then loaded, washed with 1 mL×2 of 33.3% acetonitrile. CMB-087229 was then dried and submitted for LCMS.

Results

It should be noted that data obtained in March were not identical to data obtained in July. However, the brain standard curve and mice brain samples maintain fair standard deviations and linearity, and thus, the results from the brain studies can still be quantified. In light of this data, it appears that some amount of CMB-003329 does penetrate the BBB (FIG. 8-10).

TABLE 6 CMB-087229 Brain Standard Curve Brain Extract Concentration (μg/mL) Brian Area Ratio (Mean ± S.E.) 0.05 0.148 ± 0.0007 0.10 0.268 ± 0.0087 0.50 1.11 ± 0.155 1.00 2.48 ± 0.084

TABLE 7 CMB-087229 Plasma Standard Curve Plasma Concentration (μg/mL) Plasma Area Ratio (Mean ± S.E.) 0.01 0.068 ± 0.00042 0.05 0.304 ± 0.00436 0.10 0.637 ± 0.0337  0.50 1.58 ± 0.0604

TABLE 8 CMB-087229 Plasma Standard Curve Plasma Concentration (μg/mL) Plasma Area Ratio (Mean ± S.E.) 0.01  1.210 ± 0.0374 0.025  2.068 ± 0.0316 0.05  3.554 ± 0.0775 0.10 6.429 ± 0.109 0.25 16.05 ± 0.684 0.50 30.22 ± 1.351 1.0 59.67 ± 3.379 2.5 149.2 ± 1.744 5.0 297.8 ± 7.539 10 591.9 ± 0.758

TABLE 9 Brain Brain/ Brain Brain Extract Brain concen- Plasma plasma Area concentration weight tration concentration Ratio Ratio (μg/ml) (g) (μg/g) (μg/ml) July July #2 0.292 0.121 0.470 0.257 0.0904 2.84 #3 0.384 0.159 0.432 0.366 0.0892 4.10 #4 0.453 0.187 0.399 0.467 0.149 3.13 #5 0 0 0.415 0 0 0

TABLE 10 CMB-087229 Mice Brain and Plasma Data Plasma Brain concentration concentration (Mean ± S.E.) (Mean ± S.E.) Brain/Plasma Ratio (μg/g) (μg/ml) (Mean ± S.E.) 10 min July 0.363 ± 0.105 0.110 ± 0.0342 3.36 ± 0.660

Having described some illustrative embodiments of the invention, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Numerous modifications and other illustrative embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the invention. In particular, although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. Acts, elements, and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments. Further, for the one or more means-plus-function limitations recited in the following claims, the means are not intended to be limited to the means disclosed herein for performing the recited function, but are intended to cover in scope any means, known now or later developed, for performing the recited function.

Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. Similarly, use of a), b), etc., or i), ii), etc. does not by itself connote any priority, precedence, or order of steps in the claims. Similarly, the use of these terms in the specification does not by itself connote any required priority, precedence, or order.

The foregoing written specification is considered to be sufficient to enable one skilled in the art to practice the invention. The present invention is not to be limited in scope by examples provided, since the examples are intended as a single illustration of one aspect of the invention and other functionally equivalent embodiments are within the scope of the invention. Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and fall within the scope of the appended claims. The advantages and objects of the invention are not necessarily encompassed by each embodiment of the invention. 

What is claimed is:
 1. A compound of the formula:

or a pharmaceutically acceptable salt thereof, wherein: R¹ is H; R² is H and R³ is —R¹⁰, —OR¹⁰, —SR¹⁰, —S(O)R¹⁰, —SO₂R¹⁰, —OSO₂R¹⁰, —C(O)R¹⁰, —C(O)OR¹⁰, —OC(O)R¹⁰, —OC(O)OR¹⁰, —C(O)N(R¹⁰)₂, —OC(O)N(R¹⁰)₂, a suitable amino protecting group, or an optionally substituted 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, or an optionally substituted 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, or sulfur; wherein R¹⁰ is hydrogen, halogen, optionally substituted C₁₋₂₀ alkyl, optionally substituted phenyl, optionally substituted arylalkyl or monocyclic aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, and sulfur, and wherein R¹⁰ optionally is substituted with substituents selected from halogen, C₁₋₆ alkyl, C₁₋₆ alkoxy, C₁₋₆ haloalkyl, nitro, hydroxy, amino, C₁₋₆ alkylamino, cyano, isocyano, isocyanato, and isothiocyanato substituents, providing that R³ is not benzimidazolyl and providing that R³ is not benzothiazolyl; m is 0-5; each R⁴ is independently —R¹¹, —SR¹¹, —CN, —S(O)R¹¹, —SO₂R¹¹, —OSO₂R¹¹, —N(R¹¹)₂, —NR¹¹C(O)R¹¹, —NR¹¹C(O)(CO)R¹¹, —NR¹¹C(O)N(R¹¹)₂, —NR¹¹C(O)OR¹¹, —N(R¹¹)S(O)R¹¹, —N(R¹¹)SO₂R¹¹, —N(R¹¹)SO₂OR¹¹, —C(O)R¹¹, —C(O)OR¹¹, —OC(O)R¹¹, —OC(O)OR¹¹, —C(O)N(R¹¹)₂, —OC(O)N(R¹¹)₂, or a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring optionally containing 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, wherein R¹¹ is halogen, optionally substituted C₁₋₂₀ alkyl, optionally substituted phenyl, optionally substituted aryl, optionally substituted arylalkyl or aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, and sulfur, and wherein R^(H) optionally is substituted with substituents selected from halogen, C₁₋₆ alkyl, C₁₋₆ alkoxy, C₁₋₆ haloalkyl, nitro, hydroxy, amino, C₁₋₆ alkylamino, cyano, isocyano, isocyanato, and isothiocyanato substituents; and, providing where R³ is H and m=1 or 2, R⁴ is —R¹², —OR¹², —SR¹², CN, —S(O)R¹², —SO₂R¹², —OSO₂R¹², N(R¹²)₂, —NR¹²C(O)R¹², —NR¹²C(O)(CO)R¹², —NR¹²C(O)N(R¹²)₂, —NR¹²C(O)OR¹², —N(R¹²)S(O)R¹², —N(R¹²)SO₂R¹², —N(R¹²)SO₂OR¹², —C(O)R¹², —C(O)OR¹², —OC(O)R¹², —OC(O)OR¹², —C(O)N(R¹²)₂, —OC(O)N(R¹²)₂, or a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring optionally containing 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur; wherein R¹² is halogen, optionally substituted C₅₋₂₀ alkyl, optionally substituted phenyl, optionally substituted aryl, optionally substituted arylalkyl or aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, and sulfur, and wherein R¹² optionally is substituted with substituents selected from halogen, C₁₋₆ alkyl, C₁₋₆ alkoxy, C₁₋₆ haloalkyl, nitro, hydroxy, amino, C₁₋₆ alkylamino, cyano, isocyano, isocyanato, and isothiocyanato substituents, providing where R³ is H, m=2 and at least one R⁴ is halogen, the at least one R⁴ that is halogen is mew or ortho to the C—O bond; and providing where R³ is H, m=1, and R⁴ is bromine, R⁴ is meta to the C—O bond.
 2. The compound of claim 1, wherein m is 2 and said di-substituted phenyl moiety is


3. The compound of claim 2, wherein said phenyl moiety is


4. The compound of claim 1, wherein R³ is selected from the group consisting of hydrogen and substituted or unsubstituted C₁₋₆ alkyl.
 5. The compound of claim 1 of any one of the formulae:


6. A pharmaceutical composition for treating ALS comprising a therapeutically effective amount of a compound of claim 1 and a pharmaceutically acceptable excipient.
 7. A method of treating amyotrophic lateral sclerosis (ALS) comprising administering a therapeutically effective amount of a compound of claim 1 to a subject with ALS.
 8. The compound of claim 1 wherein R³ is selected from


9. A compound of the formula:

or a pharmaceutically acceptable salt thereof, wherein: R² is H and R³ is R¹⁰, —OR¹⁰, —SR¹⁰, —S(O)R¹⁰, —SO₂R¹⁰, —OSO₂R¹⁰, —C(O)R¹⁰, —C(O)OR¹⁰, —OC(O)R¹⁰, —OC(O)OR¹⁰, —C(O)N(R¹⁰)₂, —OC(O)N(R¹⁰)₂, a suitable amino protecting group, or an optionally substituted 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, or an optionally substituted 8-10 membered saturated, partially unsaturated, or aryl bicyclic ring having 0-4 heteroatoms independently selected from nitrogen or sulfur, wherein R¹⁰ is halogen, optionally substituted C₁₋₂₀ alkyl, optionally substituted phenyl, optionally substituted arylalkyl or aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, and sulfur, and wherein R¹⁰ optionally is substituted with substituents selected from halogen, C₁₋₆ alkyl, C₁₋₆ alkoxy, C₁₋₆ haloalkyl, nitro, hydroxy, amino, C₁₋₆ alkylamino, cyano, isocyano, isocyanato, and isothiocyanato substituents, providing that R³ is not benzimidazolyl and providing that R³ is not benzothiazolyl; m is 0-5; and each R⁴ is independently R¹¹, —OR¹¹, —SR¹¹, —CN, —S(O)R¹¹, —SO₂R¹¹, —OSO₂R¹¹, —N(R¹¹)₂, —NO₂, —NR¹¹C(O)R¹¹, —NR¹¹C(O)(CO)R¹¹, —NR¹¹C(O)N(R¹¹)₂, —NR¹¹C(O)OR¹¹, —N(R¹¹)S(O)R¹¹, —N(R¹¹)SO₂R¹¹, —N(R¹¹)SO₂OR¹¹, —C(O)R¹¹, —C(O)OR¹¹, —OC(O)R¹¹, —OC(O)OR¹¹, —C(O)N(R¹¹)₂, —OC(O)N(R¹¹)₂, or a 3-8 membered saturated, partially unsaturated, or aryl monocyclic ring optionally containing 0-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, wherein R¹¹ is halogen, optionally substituted C₁₋₂₀ alkyl, optionally substituted phenyl, optionally substituted aryl, optionally substituted arylalkyl or aryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, and sulfur, and wherein R¹¹ optionally is substituted by substituents selected from halogen, C₁₋₆ alkyl, C₁₋₆ alkoxy, C₁₋₆ haloalkyl, nitro, hydroxy, amino, C₁₋₆ alkylamino, cyano, isocyano, isocyanato, and isothiocyanato substituents.
 10. The compound of claim 9, wherein m is 2 and said di-substituted phenyl moiety is


11. The compound of claim 10, wherein said phenyl moiety is


12. The compound of claim 9, wherein R³ is selected from the group consisting of hydrogen and substituted or unsubstituted C₁₋₆ alkyl.
 13. The compound of claim 9 of any one of the formulae:


14. The compound of claim 9 wherein R³ is selected from


15. A pharmaceutical composition for treating ALS comprising a therapeutically effective amount of a compound of claim 9 and a pharmaceutically acceptable excipient. 